Method and apparatus for using light emitting diodes

ABSTRACT

The present invention provides a method and apparatus for using light emitting diodes for curing in various applications. The method includes a novel method for cooling the light emitting diodes and mounting the same on heat pipe in a manner which delivers ultra high power in UV, visible and IR regions. Furthermore, the unique LED packaging technology of the present invention that utilizes heat pipes performs far more efficiently in much more compact space. This allows much more closely spaced LEDs operating at higher power and brightness.

CROSS-REFERENCE TO RELATED APPLICATIONS:

This application is a continuation of International Application No.PCT/US2003/023504 filed on Jul. 25, 2003, and which designated the U.S.,which claims benefit of priority of U.S. Provisional Application Nos.60/398,635, filed Jul. 25, 2002; 60/405,432, filed Aug. 23, 2002;60/410,720, filed Sep. 13, 2002; 60/416,948, filed Oct. 8, 2002;60/420,479, filed Oct. 21, 2002; 60/467,702, filed May 3, 2003 and60/476,004, filed on Jun. 4, 2003.

FIELD OF THE INVENTION

This invention relates to the field of light emitting diode (“LED”)technology, particularly to improvement in the output of light therefromfor curing curable compositions and forming cured parts from curablecomposition after exposure thereto.

BACKGROUND OF THE INVENTION

Heat can damage sensitive electronic components, degrading reliabilityand hampering the ability to concentrate higher power levels intosmaller packages. Many applications would benefit from the ability toclosely package LEDs into compact configurations, but the heat levelsgenerated have always been a limiting factor. As LEDs become moresophisticated, eliminating internal heat build-up has also becomeincreasingly difficult. Devices are becoming more powerful and creatingsolutions for removing the resulting heat generation often pose greatchallenges.

U.S. Patent Publication No. 2003/0036031 to Lieb et al. discloses alight-emitting handpiece for curing light-curable dental resins andsimilar materials. The device includes a head portion for supporting aLED light source, a tubular handle portion for containing a power sourcefor energizing the LED light source and a neck portion thatinterconnects the head and handle portions. The head and the neckportions are integrally formed from a common, thermally conductivematerial and operate to provide a heat sink for the LED. A substantialportion of the light source housing itself functions to dissipatesufficient thermal energy away from the LED allowing the LED to beoperated for a time interval sufficient to effect resin curing.

In U.S. Patent Publication No. 2003/0021310 to Harding, there isdisclosed a method and apparatus for cooling electronic oropto-electronic devices. The apparatus includes the device mounted on aheat sink assembly within a can having a can body and a can headerthermally coupled to the heat sink assembly and closing the can body anda thermal conductor outside the can and having a first portion attachedto at least part of an edge of the can header and a second portionattached to a thermal sink outside the can.

In U.S. Pat. No. 6,159,005 to Herold et al., there is disclosed a small,light-weight handy device for photo polymerizing synthetic materials.The device includes a built-in battery, a light source constituted by anLED which emits a small useful spectrally range only, thereby avoidingany heat radiation. The LED is preferably located at the tip of thedevice directing towards the site to be polymerized.

In U.S. Pat. No. 6,523,959 to Lu et al., there is disclosed a coolingdevice utilized to cool a liquid crystal panel and polarizer of anoptical system in a liquid crystal projector. The cooling deviceincludes a heat dissipation system comprising a plurality of heat pipesdisposed at the two flank sides of said liquid crystal panel.

None of these U.S. patent documents disclose LED cooling in a manner todissipate internal heat energy and packaging the same to achieve maximumlight output. Thus, a need exists for cooling the LEDs and mounting thesame on the heat pipes in a manner which greatly surpasses theperformance of conventional cooling techniques and benefit high-density,miniatured LED components. Furthermore, there is a need for a novel LEDpackaging technology that channels heat away via state-of-the-art microheat pipes that perform far more efficiently, and in much more compactspace, than conventional heat sink technology.

SUMMARY OF THE INVENTION

In a first embodiment of the present invention there is provided amethod and device for curing adhesives on a surface. The method includesproviding at least one LED, passing a coolant into the LED through atleast one channel to effect cooling of the LED and irradiating theadhesive on the surface with the LED to cure the adhesive. The deviceincludes a power supply, a radiation source having a radiation outputand including at least one LED coupled to the power supply and at leastone channel coupled to the LED, wherein a coolant is passed into the LEDvia the channel thereby cooling the LEDs to deliver a high light outputon the adhesives.

In a second embodiment of the present invention there is provided amethod for cooling LEDs. The method includes providing at least one LED,connecting at least one channel to the LED to create a path andinjecting a coolant through the channel to cool the LEDs.

In a third embodiment of the present invention, there is provided an LEDcuring device. The device includes a tubular body having two opposingends, an LED body including a highly conductive surface placed at oneopposing end and a heat pipe connected to the conductive surface of theLED body. The heat pipe serves to transport heat away from the LED body.

In a fourth embodiment of the present invention, there is provided adevice for transporting thermal energy. The device includes a copperheat sink, an array of LEDs and at least one heat pipe of tubular shape.The copper heat sink has at least one vapor cavity. The array of LEDsare attached to the heat sink wherein a long axis of the vapor cavity issubstantially perpendicular to the p-n junctions of the LEDs. The heatpipe of tubular shape is inserted into the heat sink via the vaporcavity, wherein thermal energy is transported away from the array ofLEDs in a substantially opposite direction from light emitting from theLED.

In a fifth embodiment of the present invention, there is provided an LEDdevice package. The LED device package includes a conductive substrate,a heat pipe connected to the conductive substrate and at least one LEDmounted onto a tip of the heat pipe, wherein heat is transported awayfrom the LED.

In a sixth embodiment of the present invention, there is provided an LEDcuring device. The LED curing device includes a tubular body, an LEDbody, a heat pipe, a power source, a fan and a heat sink/exchanger. Thetubular body has two opposed ends including a wide end and a tip end.The LED body includes a conductive surface and is placed at the tip endof the tubular body. The heat pipe extends through the tubular body andis bonded to the conductive surface of the LED body. The power source islocated around the middle portion of the tubular body for powering theLED. The fan is situated at the wide end of the body. Finally, the heatsink/exchanger is placed between the power source and the fan to receiveair blown out from the fan.

In a seventh embodiment of the present invention, there is provided anapparatus for transporting heat and/or thermal energy. The apparatuscomprises at least one heat pipe and an LED device. Each heat pipe has afirst end and a second end. The first end serves as an evaporating endand the second end is the condensing end. The LED is mounted at thefirst end of each heat pipe, wherein heat and/or thermal energy istransported in a general direction away from each LED, i.e. away fromthe first end toward the second end of the respective heat pipe.

In an eighth embodiment of the present invention, there is provided anapparatus for transporting heat. The apparatus includes a heattransporting device, an LED and a transport means. The heat transportingdevice has a first end and a second end. The LED is mounted at the firstend of the heat transporting device. The transport means is associatedwith the heat transporting device for transporting heat generate by theLED from the first end to the second end.

In a ninth embodiment of the present invention, there is provided adevice for providing light in a predetermined direction. The deviceincludes a heat pipe, an LED, a power supply, an activation switch and ahousing. The heat pipe has a first end and a second end. The LED ismounted at the first end of the heat pipe. The power supply powers theLED. The activation switch activates the power supply. The housingsurrounds at least a portion of the heat pipe.

In a tenth embodiment of the present invention, there is provided alight emitting apparatus. The apparatus includes an electricallyconductive heat pipe and an LED mounted on a tip of the heat pipe,wherein the heat pipe provides electricity for the LED and transportsheat from the LED.

In an eleventh embodiment of the present invention, there is provided anapparatus for transporting thermal energy. The apparatus includes anarray of heat pipes and an LED. Each heat pipe in the array of heatpipes has a first end, a second end and a cavity extending from thefirst end to the second end. The LED is mounted to the first end of eachheat pipe. Each LED has a p-n junction, wherein at least a portion ofthe cavity is substantially perpendicular to the p-n junction of theLED.

In a twelfth embodiment of the present invention, there is provided anLED device. The LED device includes a substrate and at least one LED.The substrate has at least one heat pipe. The LED is mounted on thesubstrate, wherein heat generated by the LED travels in a substantiallyopposite direction from light emitted from the LED.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a conventional LED device.

FIG. 2 illustrates a perspective view of a device having an array ofLEDs.

FIG. 3 shows a perspective view of a device having an array of LEDs in amold cavity.

FIG. 4 shows a device of the present invention having an array of LEDswith the electrical connection.

FIG. 5 illustrates a forced convecting cooling to a device having anarray of LEDs.

FIG. 6 a shows a perspective view of a hand held LED curing deviceaccording to the present invention.

FIG. 6 b is an expanded view of the tip end of the device in FIG. 6 a.

FIG. 7 illustrates a perspective view of a liquid-cooled version of theLED hand held curing device according to the present invention.

FIG. 7 a is an expanded view of the front end of the device in FIG. 7.

FIG. 7 b is an expanded view of the tip end of the device in FIG. 7.

FIG. 8 shows an LED curing device in which heat pipe provides bothcoolant and electrical connection according to an alternate embodimentof the present invention.

FIG. 8 a shows an expanded view of the tip of the device of FIG. 8 withmultiple LEDs.

FIG. 9 is a perspective view of an alternate light-emitting device thatis cooled by a phase change material.

FIG. 9 a shows an adhesive curing device in accordance with anembodiment of the present invention.

FIGS. 9 b and 9 c illustrate a device including multiple LED array withdetachable fins according to an alternate embodiment of the presentinvention.

FIG. 10 shows a device having an array of large area UV or visible LEDsmounted on multiple sinks and cooled by an array of heat pipes accordingto an alternate embodiment of the present invention.

FIGS. 11, 11 a, 11 b, 11 c, 11 d, 11 e and 11 f illustrate variousembodiments of a novel packaging of LEDs and heat pipes according to thepresent invention.

FIGS. 12, 12 a, 12 b, 12 c, 12 d and 12 e illustrate various embodimentsof the LED/heat pipe assembly according to the present invention.

FIG. 13 shows a perspective view of the LED/heat pipe device on acircuit board.

FIG. 14 shows an array formed of more than one device of FIG. 13.

FIG. 14 a is a cross-sectional view of the arrayed devices of FIG. 14.

FIGS. 14 b, 14 c and 14 d illustrate devices having multiple heat pipeswith different spacing and geometric patterns including multiple LEDs.

FIG. 14 e shows the devices of FIGS. 14 b, 14 c and 14 d placed in thecircuit board.

FIGS. 14 f and 14 g show a device having a single heat pipe includingmultiple LEDs connected to a circuit board.

FIGS. 15 a and 15 b illustrate a perspective view of multiple LEDs onheat pipes arrayed on a circuit board.

FIG. 15 c is a side view of two heat pipes of FIG. 15 b in the circuitboard.

FIG. 15 d illustrates a forced-air cooled hand held device according toan embodiment of the present invention.

FIG. 15 e shows a perspective view of multiple LEDs disposed on the endof the heat pipe.

FIG. 16 shows a device where vertical cavity surface emitting laser(VCSEL) is bonded to the heat pipe in an alternate embodiment of thepresent invention.

FIGS. 17 and 17 a illustrate an exploded view of a heat sink bonded tothe heat pipe according to a preferred embodiment of the presentinvention.

FIGS. 18 a, 18 b, 18 c, 18 d and 18 e show a perspective view of LEDmounted on to various portions of the heat pipe.

FIGS. 19 a and 19 b illustrate packaged LED device on a circuit board.

FIG. 20 shows a perspective view of a first circuit with a center cutout for bonding of LEDs.

FIG. 20 a shows a bottom view of the circuit of FIG. 20.

FIG. 20 b shows a perspective of a second circuit with a center cut out.

FIG. 20 c shows a bottom side of the circuit of FIG. 20 b.

FIG. 20 d shows the first circuit of FIG. 20 and the second circuit ofFIG. 20 b bonded together.

FIG. 20 e shows the bottom side of the two bonded circuit of FIG. 20 d.

FIG. 21 illustrates a perspective view of the first circuit of FIG. 20with multiple LEDs.

FIGS. 22 and 22 a show a ring assembled on top of the first circuit ofFIG. 20.

FIG. 22 b illustrates the assembly of FIG. 22 a with a TIRlens/reflector.

FIG. 22 c illustrates a bottom view of the assembly of FIG. 22 b.

FIG. 22 d shows a perspective view of the assembly of FIG. 22 c with thefirst circuit.

FIG. 22 e shows a perspective view of the assembly of FIG. 22 d with astrengthening ring and the heat pipe.

FIG. 22 f shows a bottom view of the assembly of FIG. 22 e illustratingalternate electrical connections.

FIG. 22 g illustrates a complete assembly with the assembly of FIG. 22 daffixed to the assembly of FIG. 22 f.

FIG. 22 h shows an exploded view of the lens of the LED including aconcavity according to a preferred embodiment of the present invention.

FIGS. 23 a and 23 b show an array of heat pipes inserted into thecircuit board.

FIG. 24 illustrates the LED array assemblies of FIG. 22 g being insertedinto the circuit board assembly of FIG. 23 a.

FIG. 25 shows the assembly of FIG. 22 b and the assembly of FIG. 22 dwith a protective outer sleeve.

FIG. 26 a illustrates a perspective view of various parts of the circuitboard device prior to packaging and assembly with LEDs.

FIG. 26 b shows an array of LED packages according to the presentinvention after the packages have been assembled and singulated.

FIG. 26 c shows an exploded view of one post-singulation LED packageaccording to the present invention.

FIG. 27 shows an expanded view of an individual LED package of FIGS. 26a, 26 b and 26 c.

FIG. 27 a shows a bottom-side view of the individual LED package of FIG.27 with the bottom layer including a highly thermally conductivematerial.

FIGS. 28 a and 28 b show a side view of the individual LED package ofFIG. 27.

FIG. 29 shows a bottom-side view of the individual LED package of FIG.27 with the heat spreader.

FIG. 30 a illustrates a perspective view of a flattened heat pipe withLEDs.

FIG. 30 b illustrates a perspective view of a flattened heat pipe withLEDs.

FIG. 30 c illustrates a perspective view of the heat pipe bent around afinned sink.

FIGS. 31 a and 31 b illustrate a perspective view of an array of LEDsbonded on a diamond substrate with a heat pipe according to an alternateembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION:

The present invention provides high power LEDs and heat pipe technologywhich allows for ultra-high power density packaging. The ultra-highthermal conductivity of the heat pipe allows for over-driving the LEDsby a factor of 4x, while maintaining junction temperatures well withinrated limits. Other attributes include low thermal resistance submount,brightness-maintaining TIR reflector, low cross-sectional area heatsink, and individually addressable high-density chip array. Theseattributes facilitate the ability to achieve high power densities, evenwithout integral heat pipes, which is especially useful for thoseapplications that do not demand ultra-high thermal performance.

The manner of bonding of the LED device to the heat pipe component as inthe present invention minimizes the physical space requirements whiletaking advantage of heat pipes' unique rapid heat dissipationcapabilities. This allows much more closely spaced LEDs operating athigher power and brightness. Some other features of this heat pipepackaging for LED components include rapid thermal response, variableheat flux, lightweight, high reliability and requires little or nomaintenance.

In one aspect of the present invention, there is provided a novel meansof cooling the light emitting devices preferably at least one LED ororganic LED (“OLED”) or flexible OLED (“FOLED”) or Flip Chip LED(“FCLED”), or vertical cavity surface emitting laser (“VCSEL”). For thepurpose of the invention, we will refer to the LED, however, it is to beunderstood that other light emitting devices mentioned or known in theart can be used as well. Referring to FIG. 1, there is shown a singleemitter LED 10 preferably manufactured by Lumiled Inc. It is understoodthe LEDs from other manufacturers may be substituted. This particularLumiled emitter is referenced for example only. It has a “low dome” lenson it in the drawing but a “high dome” (lambertian lense), no lense,GRIN lense may be employed. Also, the wavelength in this example is“Royal Blue” which is approximately 460 nm. Other wavelengths from 200nm to 11,000 nm may be used. The most preferable wavelength range is 250nm to 5,000 nm in the instant invention.

The LED 10 in FIG. 1 typically includes a “clipped” anode 11 and cathode12 legs to facilitate easier electrical connection with a substantiallyround flexible hook-up wire bonded to the anode and cathode withthermally and electrically conductive adhesive. Element 14 is a highlyconductive submount/slug between the anode 11 and the cathode 12, whichis both thermally and electrically conductive. A hole 13 with smallthreadlike protrusions is drilled through the conductive slug 14 of LED10. The threaded through hole 13 goes all the way through the highlyconductive submount/slug 14, preferably formed of copper. A plastic ring15 holds the slug 14 and the LED lens in place. The inner diametercircumference of the hole 13 is preferably within 0.010″ of the chipmounting surface.

FIG. 2 depicts a device including an array of six LEDs 10 arrangeddesirably in semi-circle of potted polymer 20 sharing a common coolantpath. The polymer 20 is preferably a shore A durometer UV thermal cureacrylic-urethane or silicone elastomer. The inner semi-diameter is closeto, or touching, the surface to be cured or processed. It is understoodthat many different lensing concepts in addition to the one depicted maybe employed. The polymer refractive index can preferably range anywherefrom n=1 to n=2, most preferred is 1.5. Different shaped domes ofdifferent refractive indexes (or the same) as the polymer(s) may beused. No domes, GRIN, etc. may also be used. The six emitters 10depicted are by way of example only. One single emitter to 100 for eachrow may preferably be employed. Also, the radiation pattern does nothave to be substantially lambertian. Various focusing and/or scatteringtreatments may be employed. For scattering a textured surface on thepolymer or polymers as well as bubble or beads within the polymer matrixmay be employed. The emitters 10 may be arranged so that the opticalradiation pattern is advantageously employed on the desired area.Coolant (gas or liquid) 21 enters into the device via channel 29 and isdirected by channels 22 and 23 into the emitters 10 which havepreferably lightly threaded through holes 13 (not shown) to enhancethermal transfer by way of boundary layer break-up. Channel 29 alsoserves as an exit channel for coolant to exit the device. Channels 24,25, 26 and 27 connect one LED 10 from another serving to pass thecoolant from one LED 10 to another. Channels 28 a and 28 b are 180°return bends from each LED 10 located at the end of the array returningthe coolant back to the channel 21. All these channels act as coolingchannels with coolant passing from channels to the holes 13 of the LEDs10, thereby cooling the LEDs 10 and high heat transfer rates can beobtained.

Referring to FIG. 3 of the present invention, there is shown six LEDs 10in a mold cavity 30 preferably formed of aluminum. A low melting pointmetal wire is encapsulated in polymer and then melted out for a compacthigh power density array of LEDs or VCSELs. Specifically, a low meltingpoint solder wire that is approximately 0.030″ diameter is fed througheach of the pre-drilled (0.033″ diameter) and threaded (0.9 UNM) holes13 (not shown) in the integral copper slugs 14 (not shown) of the LEDs10. Two wires are threaded through the holes in the LEDs and two endsare formed into one 32 and the other two ends are also formed into one33 as shown in FIG. 3. It is important that the initial two wires thatform 32 do not ever touch the wires that form 33′ They may be UV tackedin place using 0P30 UV adhesive. Electrical connections are then madewhich will be explained with reference to FIG. 4. Referring back to FIG.3 (after the electrical connections are made in FIG. 4), a flexiblepotting adhesive/polymer 20 is poured into mold 30 so that it covers allthe aforementioned parts/wire. The flexible potting adhesive/polymer 20is UV cured with an optional thermal cure at a temperature of 70° C. Thecured polymer assembly is removed from the mold 30 and submerged in aheated liquid to approximately 70° C. and the wire is melted out (it isbest to first coat the wire with mold release). Now a coolant path isformed between and through all the parts so that during deviceoperation, coolant can be injected through hole 34 a of an inlet coolingtube 34 which passes through channel 28, thereby cooling the LEDs 10 andit will come out hole 35 a of an outlet cooling tube 35 after it hascirculated through and cooled all the parts of the LED 10. It isunderstood that the cooling loop could be either series or parallel.This ability of cooling of the LEDs causes a substantially higher lightoutput, hence fewer LEDs need to be used.

FIG. 4 shows the device of the instant invention out of the mold 30 forclarity and further showing the electrical connection. The LEDS 10 areconnected in parallel, however, it is understood that the LEDs couldalso be connected in series. Also many (20 plus) individual small areaemitter chips could be substituted for the large area power LEDs. Astranded flexible “hook-up” wire which is about 0.039″ in diameter andapproximately 2″ to 3″ long is pushed into and against the cathode taband case of the LED. The 0.039″ diameter wire is bonded to the LEDcathode tabs 42 a-42 e with electrically conductive epoxy therebyconnecting the LEDs 10 electrically. A similar treatment is done to theanode tabs 44 a-44 e. Finally, a 3′ long wire 45 is bonded to thecathode wire 46 and a 3′ long wire 47 is bonded to the anode wire 48.Again, this is put into the mold cavity 30 in FIG. 3 prior to the UVcure polymer 20 being poured in and cured.

FIG. 5 depicts six LEDs encapsulated in a polymer arch (semi-circle).The electrical and coolant connection channels are also shown. The powerdensity on the surface to be cured or processed can be addressed now. Itshould be from approximately 5 mW to 500 W per square cm, and this is inreference to all embodiments described in this patent application. Inthe preferable embodiment the power density is approximately 100 mW to 2W per square cm. In the most preferable embodiment the power density isabout 400 mW to 500 mW per square cm. It is feasible to have excellentcooling characteristics in the present invention in excess of severalwatt CW output power per light emitting device. FIG. 5 shows inletcooling tube 34 and output cooling tube 35. These cooling tubes 34 and35 can preferably be connected to a pump 50 and move coolant through thedevice and then to a reservoir or chiller or heat exchange or all three52. This process is referred to as forced convection cooling in whichthe coolant (i.e., water) being fed to the device via inlet cooling tube34 is aided by the force of a pump. The power leads 54 and 56 canpreferably be connected to a power supply or a battery 58.

In another aspect of the present invention, there is provided a methodfor mounting and cooling LEDs and devices for same that may be used forcuring adhesives or composites and other light source uses.

Referring to FIG. 6 a, there is shown an LED curing device 60. Thedevice 60 is preferably a hand LED curing device. The device 60 includesa tubular wand body 62 made of plastic or metal having two ends a wideend 62 a and a tip end 62 b which is bent. Please note that the tip end62 b of the body 62 need not necessarily be bent. LED 10 is located atend 62 b of the body 62. A heat pipe 64 extending through body 62 isbonded with glue or solder inside the conductor slug 14 preferably ofcopper of the LED 10, although no cavity or hole need be made in theconductor slug 14. As shown in FIG. 6 a, the heat pipe 64 may bemodified to “neck” down at the end 62 b. Also a flattened heat pipe maybe used and the LED is bonded on top of the flattened end. An optionalbattery pack 61 a and 61 b may preferably be driven by a wall plugtransformer not shown, around middle portion of the body 62. A fan 66that is approximately 30 mm² may be located at the end 62 a of the body62. A heat sink 68 preferably of Al or Cu is glued to “cold end” of theheat pipe 64 between the fan 66 and the battery back 61 a and 61 b. Thefan 66 is used to blow air over the heat sink 68 and exhausted throughports (not shown) in the body 62 that most components are mounted in.Switch 63 controls the electrical current to the LED via wires (notshown) connecting the battery pack 61 a and 61 b to the LED 10. The LEDlense 10 a is shown surrounded by pambolic reflector 10 b and optionaladditional lense 10 c. The heat pipe 64 is a closed container into whicha small amount of liquid (working fluid, typically water) is injectedunder vacuum. The inner walls of the container of the heat pipe 64 arelined with capillary-action material (wicking structure). When a portionof the heat pipe 64 is exposed to heat produced by LED 10, the fluid inthe heated portion i.e., hot end of the heat pipe 64 vaporizes pickingup latent energy. The vapor flows to the “cold end” of the heat pipewhere the vapor cools and condenses releasing latent energy and thecondensed fluid is returned by capillary action to the hot end. The heatpipe 64 serves as a heat engine taking heat away from the LEDs 10.

FIG. 6 b is an expanded view of the tip end 62 b of the device 60 inFIG. 6 a. The “pocket” 65 is shown wherein the heat pipe 64 is milled,drilled, molded, etc., in the slug 14 of the LED 10 such that it is onlya few 0.001's of an inch greater diameter than the heat pipe 64. Highthermal conductivity epoxy is placed in the bottom of the pocket 65prior to the insertion of the heat pipe 64. The operation of a heat pipe64 is as discussed above, known by those skilled in the art of heattransfer but has not been used prior to this invention in a hand heldLED device 60 for curing. Also in the prior art, the heat pipe 64 hasnot been inserted into or onto the slug 14 or submount of an LED 10 asshown, and also not used for the purpose of mounting an LED 10 at theend of a wand 62 having a small diameter of around 8.5 mm Ø. Most LEDslugs are glued or soldered to a large PCB board or large, flat heatsink which is incompatible with the application of the LED device 60described herein. It is understood that the heat pipe 64 could besoldered or glued to the LED “slugs” without the “pocket” 65 or aseparate heat pipe could be bonded to the LED.

In the above discussed embodiment of FIGS. 6 a and 6 b of the presentinvention, the heat pipe 64 transports heat in a direction that is notsubstantially perpendicular to the p-n junction of LED 10. The end ofthe device of FIGS. 6 a and 6 b that includes the LED 10 and reflector106 mounted on the tip of the heat pipe 64 and surrounded by a sleeve,is bent at 45° about 7 mm from the end of the device. The light istraveling away from the p-n junction plane in a substantiallyperpendicular direction, (if it were collimated,) but the majority ofthe length of the heat pipe, and therefore the direction the heat istransported, is not perpendicular due to the 45° bend in the heat pipe64. If there were no 45° bend (i.e. straight) the heat would flow in asubstantially perpendicular direction to the p-n junction.

FIG. 7 shows a liquid-cooled version of the LED hand held curing device60. By utilizing liquid cooling, the wand 62 (long, slim tube) may bemade flexible by using flexible liquid carrying tubes. Wavelengths from200 nm to 11,000 nm could preferably be used including “white” LEDs. TheLED body 10 is shown with an attached tense 10 a. The LED 10 is locatedat the end of wand 62 that is approximately 8.5 mm Ø and can beflexible, semi-rigid or rigid. Coolant tubes 34 (inlet) and 35 (outlet)are bonded to an optional threaded through the hole 67 in the slug ofthe LED 10. In this way coolant is passed through the LED 10 atapproximately 2 psi to 50 psi for the purpose of cooling the LED die(not shown, but bonded to one end of the conductor slug 14). The coolanttubes 34 and 35 are attached respectively to the pump 50 which suppliesthe coolant (i.e., liquid) and a finned heat exchanger 52, whichreceives the heat. Fan 66 is the drive electronics for pump 50. Fan 66passes air over the external fins of heat exchanger 52 and the air isdischarged through ports (not shown) in the molded plastic housing ofthe body 62. No electrical leads are shown for drawing clarity. Batterypack 61 a and 61 b is shown. The device may be operated strictly frombatteries or may have a cord to a wall mounted transformer. The purposeof the liquid cooling is to be able to remove the heat generated by theLED die 10 that is in a very small area and “pump” the waste heat to alarger area, the heat exchanger 52 via the heat pipe 64. Using thistechnique, LEDs may be driven at higher operating currents and outputpower than if they were mounted to a flat heat sink and/or PC board(PCB). Additionally, it is difficult to have a heat sink of PCB out atthe end of an approximately 8.5 mm Ø diameter wand that is needed to getinto “tight” spaces in an electronic assembly glue curing application ora patient's mouth for curing or whitening. Also very important, is thefact that it is easy to make “wand” that is flexible if liquid coolingis used to transport heat at high flux from one end of the wand to theother.

FIG. 7 a is an expanded view of FIG. 7 wherein the inlet and outlettubes 34 and 35 respectively, are more clearly shown. These tubes areavailable from HV Technologies (North Carolina) with a thin spiral orcoil wire in the wall for kink resistance. 90° bent tubes 71 and 73 areglued into the through hole 67 in the conductor slug 14 to pass thecoolant from the inlet tube 34 into the LED 10 and similarly to send thecoolant out of the LED 10 into outlet tube 35. The approximately 8.5 mmØ tube wand 62 may be rigid or flexible depending on the application.Curing industrial/photonic adhesives could be accomplished by using aflexible “mono-coil” type outer tube that would carry the coolant tubes34 and 35 and electric wires to the LED 10 at the end. The “mono-coil”would then serve as a sort of replacement for a light-guide for curingequipment. The LED 10 at the end could also be replaced by an edgeemitting laser diode or VCSEL. The LED 10 may be driven at highercurrents than would be possible with just a heat sink, and is especiallyuseful in small, contained areas where it is difficult to cool highpower density devices and areas where a flexible light source isadvantageous.

FIG. 7 b is an expanded view of another embodiment for the instantinvention. Here the LED 10 has a coolant inlet hole 75 in the center ofthe conductor/slug 14 and a feeding inlet tube 34 is shown. The inlethole 75 is bi-sected by one or more outlet holes 75 a and 75 b near thebottom or end of the hole 75. This arrangement allows for lower thermalresistance cooling as the inlet hole 75 serves to “impinge” coolant onthe area of the conductor/slug 14 at the bottom of hole 75 that isimmediately below the LED “die” (not shown for clarity). The outletholes 75 a and 75 b (two more outlet holes are not shown for clarity)allow the heated coolant to escape with minimal back pressure where itis returned via pump 50 to the heat exchanger 52 (or chiller). It isunderstood that all these embodiments do not necessarily have to be handheld. A “5 W” LED may preferably be driven with two to six times thecurrent with this technology. Multiple arrays or single LED 10 (or laserdiode) units may use the same cooling techniques described in theinstant invention for static or stationary wall or bench-top units formay applications where a light source of high intensity in a tight spaceis required beyond just curing.

In an alternate embodiment of the present invention, there is provided aLED device wherein the LED die is mounted and/or bonded to the tip of aheat pipe, where the heat pipe may have the function of an anode orcathode in addition to its heat sinking and transport functions. ThisLED/heat pipe invention has broad applicability when used with UV orvisible LED packages and/or individual die or combinations of each suchas in UV lamps for curing adhesives and various other applications.

Referring to FIG. 8, there is shown the heat pipe 64 having an averagerange of the diameter of preferably between 3 and 6 mm and averagelength preferably ranging between 25 mm and 500 mm. The LED chip (ordie) 10 is shown bonded to the tip of the heat pipe 64. The heat pipe 64may be flattened to accommodate the flat die. It is understood thatpackaged LEDs, i.e., presoldered to heat sinks or slugs could also beused. If the conductor slug 14 is used it may have a female contour init to accommodate the end of the heat pipe 64. The heat pipe 64 itselfmay be the electrically charged anode 11 and a wire bond may be made ontop of the LED die as shown in FIG. 8 to make the cathode wireconnection 12. These functionalities could also be reversed. In thismanner, the heat pipe 64 provides an electrical connection to the LED 10in addition to cooling the same. The heat sink 68 may be bonded to thecondensing end of the heat pipe 64 and an optional fan 66 to blow airserving as the cooling medium over the heat sink 68.

In FIG. 8 a, the heat pipe/heat sink is shown with multiple LED dies 10.They may be connected in electrical series or parallel or beindividually addressable. The dies 10 may emit one or more centeredwavelengths. A shaped, molded or potted polymer or glass or ceramiclense 81 is shown and it may encapsulate the LED dies 10 and ispreferably made from a UV degradation resistant polymer. The arrows 82depict the light emission from the LED(s) 10. Element 84 depicts a vaporcavity that extends down the center of the interior of the heat pipe 64.It is substantially parallel to the outside diameter sides of the heatpipe 64. The LED cathode and anode surfaces (p-n junction) aresubstantially perpendicular to the heat pipe vapor cavity 84 axis of theheat pipe 64 which is substantially straight and unbent. The heat pipe64 may be bent in may different shapes for many lighting applications.

FIG. 9 is a hand held LED curing device 60 having a plastic housing thatincorporates at least one LED die 10 or at least one pre-packaged LEDdevice that is bonded to the evaporating end of a heat pipe 64. Cathodewire 12 is bonded to the cathode side of the LED die (not shown).Element 20 is a transparent material that is preferably a UV resistantpotted or molded polymer as discussed and shown earlier in FIG. 2.Again, element 63 is the electrical on/off switch. Element 92 is asurface including a gel material that preferably contains hydrogenperoxide and also preferably a photosensitizer, photoinitiator, orchromophor that the actinic light from the LEDs “activate”. Element 94is a phase change material that is preferably a paraffin material whichis placed between heat pipe 64 and the rest of the part of the deviceoutside the heat pipe 64. When the LEDs 10 are turned on, the waste heatwill flow down the heat pipe 64 and melt the paraffin 94 after apredetermined approximate time. The paraffin 94 will melt, i.e. changefrom solid to a liquid and expand and “break” the electrical circuitthat is formed between the batteries 61 a and 61 b (which may have adifferent orientation than shown, i.e., upside down) the electricallyconductive piston 96 and spring 98, the electrically conductive(preferably water filled copper) heat pipe 64 (which, in essence becomesthe anode), the LED die 10 (or pre-packaged LED device) and the cathodewire 12. This phase change will help conduct heat away from thecondensing end of the heat pipe 64. In this case, instead of fan,paraffin 94 will absorb heat from the heat pipe 64. Furthermore,paraffin 94 absorbs heat energy without raising temperature when itmelts and cools down. Again, this process works best for short dutycycle application. The novelty of this embodiment is the ability torapidly transport heat from the LED 10 through a heat pipe 64 past thebatteries 61 a and 61 b and to a forced convection cooling (or alsonon-forced convection in another embodiment). For short duty cycleapplications the heat pipe 64 (preferably porous) can be surrounded by aphase change material, such as paraffin, to absorb heat as will bedescribed in greater detail with reference to FIG. 9 below.

FIG. 9 a shows an adhesive curing device embodiment of the presentinvention. As in other embodiments, a CVD Diamond heat spreader 230 asshown in FIG. 19, is optionally positioned between the LED 10 and theheat pipe 64 in the wand tube 62, which is anodized. If the anodizedwand tube 62 is not used, the heat pipe 64 can preferably be coveredwith ˜0.002″ thick polyester shrink wrap. Here, the heat pipe 64functions as the anode 11 to the LED 10. LED 10 is optimally soldered tothe CVD heat spreader 230 which in turn is conductively glued to the endof the heat pipe 64. Cathode wire 12 is bonded to the LED 10 and theparabolic reflector 10 b. As in other embodiments, a phase changematerial 94 (usually paraffin) can preferably be communication with theheat pipe in order to further dissipate the heat being generated by theLED 10 and transported along the length of the heat pipe 64. Here, thephase change material 74 is also in communication with copper wool 95,which further dissipates heat throughout the phase change material 74due to the high thermal conductivity of the copper wool. This embodimentis shown to include lithium batteries 96 but, as in other embodiments,power could instead be supplied to the device of the present inventionusing a power cord of some kind.

FIGS. 9 b and 9 c depict an LED array for use typically in ultravioletcuring applications. This embodiment is composed of a number of LEDs 10disposed upon a slug 14 with a blind hole into which the heat pipe 64 isfixably and/or detachably inserted. Fins 208 as more clearly shown inFIG. 12 a are optionally included. Fins 208 are preferably bonded withsolder 110 or a high thermal conductivity glue. The fins 208 furtherdissipate the heat transferred from the LED 10 to the heat pipe 64. TheLEDs 10 are attached to the slug 14 via bond pads 214 via bond wires 212as more clearly shown in FIG. 14 b, and may be electrically powered inseries, in parallel, or as individually addressable entities. The numberof LEDs 10 that may be used in this type of an embodiment is limitedonly by the size of the slug 14 and the heat transport capacity of theheat pipe 64 in combination with any other heat dissipation mechanism(such as the fins 208). It is easy to envision an embodiment wherein thesingle heat pipe 64 is replaced by a number of separate heat pipes ofsimilar or varying size, all of which are in communication with anynumber of LEDs 10 via a single slug 14. It is noted that two fins 208are shown but more than two fins 208 are possible. Positive 97 andnegative 97′ gold contacts wrap around the edge of the slug 14. Alsonote that LEDs 10 are shown in series, but may also be in parallel.

In another embodiment, the device of the present invention is preferablyused UV curing applications where the heat pipes are located indifferent orientations wherein the hot end has the LEDs and the cold endis in a heat sink. The heat pipe in these embodiments is somewhatanalogous to the function of a light pipe or lightguide except that ittransports heat instead of light, and the source of light is at theoutput tip of the heat pipe.

In an additional aspect of the present invention, there is provided adevice used to cure UV inks and coatings and adhesives. The deviceincludes an array of large area UV (or visible) LEDs that are mounted onheat sinks) which are cooled by an array of (circular or flat) heatpipes that are themselves cooled by one or more fans as described indetail below.

Referring to FIG. 10 there is shown a device 100 having an array of LEDs10 which are soldered to one or more heat sinks 68, preferably formed ofcopper. The heat sinks 68 are electrically isolated from each other bythin strips of Kapton 101 or other non-conductive material that havethin layers of adhesive on both sides 102 and a layer of copper foil 103sandwiched in between. Each LED 10 has a wire bond 104 that attaches tothe copper foil 103 of the heat sink 68. All copper foil layers 103 arebrought to form the cathode common electrical connection. For everyapproximately 11 mm of electrode length there are three approximately 3mm Ø blind holes 107 drilled in each electrode 109 (only one of 90 arenumbered). An approximately 200 mm long by 3 mm Ø heat pipe 64 isinserted with an electrically conductive compound in each hole 107. Theheat pipe condensing (cold) ends are inserted in a top plate 108 andattached with an electrically conducting compound such as conductiveepoxy. This top plate 108 serves as the common electrical anodeconnection. Depending on the design of the LEDs the polarity of theelectrical connections can be reversed or modified. The current path asshown, is through the top plate 108, down the heat pipes 64, through theelectrodes 109, through the LEDs 10, through the wires 104, and outthrough the copper foil 103. It is understood that electrodes 109 couldbe monolithic with circuit “traces” for a cathode connections, or theycould be electrically isolated from the heat pipes 64 and the LEDs 10could be bonded directly to the heat pipe tips (ends), which is mostapplicable if there is a through hole (rather than blind hole) inelectrodes 109.

Glass may be ion beam sputtered over the LEDs 10 for index matchingpurposes. Gold may be electroplated onto the copper surfaces for ease ofwire bonding and die bonding. A single point, diamond-turned, fly-cutpass may be made over the bonded three electrodes 109 to create a small,flat, die-bonding surface. Lastly, a glass plate (cover slide) may beplaced over emitting LEDs 10 to protect them. The glass may behermetically seated and have a sub-wavelength structure on it foranti-reflection purposes. Also, flat plates (thinner than the top plate)can be installed to increase surface area. Preferably one or more 100 mmfans on each side of the heat pipe array cool the heat pipes in a pushme-pull me arrangement. The optional flat plates can be orientedparallel to the airstream (from fan(s) or blower(s)). It is to be notedthat in FIG. 10, the LED 10 repeat down length of device in groups ofsix and only 18 LEDs of approximately 540 LEDs are shown for drawingclarity. However, different quantity and sizes of LEDs 10 may preferablybe used.

The heat pipes are preferably oriented vertically so that the wickingaction is enhanced by gravity. The heat pipe (or heat pipes) may have anadditional bonded heat exchanger (or heat sink) with fins surrounding it(for added surface area) or it may be stand-alone (no bonded heat sinksor fins). When an array of heat pipes are employed each heat pipeessentially becomes a “pin” in a so called “pin-fin” array heat sink todissipate thermal energy from the LEDs over a large area. The heat istaken in by the heat pipe 64 at the end where LED is placed and spreadout in the entire surface area of the heat pipe which preferably isbetween 2-8 mm in diameter. In the preferred embodiment the heat pipetransports the heat away from the p-n junction of a diode in a directionthat is substantially perpendicular to the junction. It must be stressedthat because heat pipes can be bent in most any shape or form, it mustbe understood that the heat pipe could transport heat in a directionthat is not substantially perpendicular to the junction. The vaporcavity in the heat pipe may have only a portion that is nearlyperpendicular or nearly parallel to the p-n junction. Also, only aportion may be nearly perpendicular or nearly parallel to the emittedlight from a light emitting device. The aforementioned word “nearly” maybe substituted with “substantially”. Also, the term “heat” can be usedinterchangeably with “waste heat”, “thermal energy”, etc. One or moreheat pipes (arrays) cooling one or more light emitting devices (arrays)may be of small (preferably less than 2″ square inches) of large(preferably more than 2″ square inches) dimensions thus used for avariety of medical and industrial uses such as curing adhesives. Forcuring adhesives, an apparatus similar to FIG. 10 is ideal for allapplications that a microwave (electrodeless) lamp is currently usedfor.

The inner diameter (“ID”) along the length of the heat pipes iscomprised of a hollow vapor cavity 84 as shown earlier in FIG. 8. Thelight from the LEDs is generated at the “p-n” junction which isepitaxially grown in layers on a preferably GaN wafer which is dicedinto chips. The chips may be bonded to the electrodes “p” side down.Other wafer types are SiC and sapphire. Other means for forming p-njunctions other than epitaxial may be employed. Different styles andsizes and manufacturer of LEDs may be substituted for those describedand depicted in the figures. As discussed earlier, the cold ends of theheat pipes 64 can be cooled by a coolant (liquid or gas). The electrodes109 could also be liquid cooled and have internal channels therein.

In an additional aspect of the present invention, there is provided anovel LED packaging scheme and process for making same which results ina very simple, inexpensive and compact package. This advantageouslyallows the rapid transport of thermal energy away from a high energydensity heat source such as an LED chip, to a very large surface areaheat sink while minimizing the size of the heat source and the frontal,cross-sectional area of the heat sink surrounding it. This fast thermaltransport most preferably allows the operation of LED chip(s) at athreefold to fivefold (or more) increase in power over standard packagedchips while keeping the operating (junction) temperatures well withinrated limits. Also, since brightness can be defined as the “power persolid cone angle of light,” when increasing the chip power whilemaintaining the same cone angle, brightness is increased. This inventioncombines high brightness LED chips and highly effective heat pipes in anovel packaging scheme and process for making same which results, notonly in the ability to operate the LEDs at unprecedented brightness, butalso unprecedented cost per watt. Essentially, one chip is outputtingthe power of three to five chips (or more), not in the area of three tofive chips, but in the area and cone angle of a single chip, withminimal heat sink area consumed around the periphery of the chip. Thissmall frontal cross-section results in the ability to use compact andefficient lenses and reflectors that can take advantage of the chip'sbrightness in the most efficient, effective and space saving waypossible. The devices depicted in this application may contain at leastone infrared (“IR”) die and the emitted light may be used for curingadhesives or coatings by heat instead of the more common UV or visiblephotoinitiated chemical reaction. The LEDs may be used individually orin array form with one or more heat pipes either in a unit that ishand-held, fixed, or some combination of both. The present inventionmost preferably combines mainstream IC packaging technology, circuitboard technology, and power LED technology in a novel configuration thatprovides solutions to a broad array of light curing applications anddevices.

These applications and devices advantageously utilize the primaryattributes of the technology which is high brightness and power in avery compact and cost effective package.

Referring to FIG. 11, there is shown a LED 10 bonded to the tip of atleast one heat pipe 64. The LED(s) 10 is(are) affixed to the heat pipe64, by a solder or an adhesive 110 such as indium or tin, lead/tin, orgold/tin that is preferably electrolitically deposited to the heat pipe64. The solder process my use flux or be “fluxless”. The square (orother geometrical shape) is defined by an exposed and developed area ofthe electrophoretic photoresist 111. The flux process must be compatiblewith the photoresist. This photoresist layer 111 also acts as adielectric (insulating) layer. The heat pipe 64 is adhesively bonded tothe inner diameter of tube 112 comprised of conductive material,preferably aluminum. The tube 114 may be anodized and it can act as thecathode to the device when the wire 113 is bonded or mechanicallyaffixed to it in an electrically continuous manner. The diamond-turnedor injection molded elliptical or parabolic total internal reflection(“TIR”) reflector 10 b is placed over the LED 10. It has an index of˜1.53. The TIR reflector may be a Dielectric Totally InternallyReflecting Concentrator (DTIRC), a Compound Parabolic Concentrator(CPC), an Elliptical Concentrator (EC), a Compound EllipticalConcentrator (CEC), or a Compound Hyperbolic Concentrator (CHC). All ofthese may have flat or curved exit apertures. If curved, an asphericsurface may be employed. If flat, a diffractive surface may be employed.These reflectors also have the unique ability to mix multiplewavelengths that may be emitted from multiple light emitting devicesinto a homogeneously mixed beam of light. We refer to this uniqueattribute as a “color mixing TIR” reflector. The space for the LED 10 isan integrally molded, concave female preferably hemispherical surface114 that is filled preferably with a high index silicone polymer orother transparent material. This high index polymer may preferably be˜1.6 or greater. The refractive index between reflector 10 b and thesurface 114 can preferably add optical power and bend light rays to staywithin the critical angle for TIR. An anti-reflection (AR) coating maybe ion beam sputtered (or other process) on the plane (or curved)emitting surface of the TIR reflector 10 b. The vapor cavity 84 of theheat pipe 64 is shown and is only approximated. In the preferredembodiment of the invention, the heat pipe 64 of a conductive material,preferably copper, may act as the anode (although it could be cathode oreven electrically neutral or some combination of all three). Aconduction path can be traced from the batteries (not shown), throughthe heat pipe 64, through the solder 110, through the LED 10, throughthe wire 113, into the insulated sleeve tube 112, and back to thebatteries (not shown) through the electrically conductive heat sink(s)(not shown) after passing through a switch (not shown). The wire 113 isbonded to the inner diameter of the insulated sleeve 112 with a smalldot of electrically conductive adhesive 115. FIG. 11 depicts only oneLED die 10 but multiple LEDs 10 at the same or multiple or variedwavelengths may be employed. The dielectric layer 111 electricallyinsulates the electrically active heat pipe 64 from the electricallyactive sleeve 112. The sleeve may be desirably anodized aluminum with anunanodized spot underneath glue dot 115 so as to form a currentconduction path from the wire 113 to the tube 112. A small gap 116 mayor may not exist and it may be filled with a material such as thermallyconductive or thermal insulating adhesive. This may be advantageous ifthe tube 112 and heat pipe 64 are bent near the tip at an angle ofapproximately 30° to 45°. The wick structure 127 shown in FIG. 11 f ispreferably small, axially extruded grooves but it may be a screened-wickor sintered (powdered) metal wick. An AR coating or sub-wavelengthstructure may be employed on the exit aperture 118. LED light emissionis depicted by arrow(s) 117 which are shown undergoing TIR at thereflector wall/air interface. Light emitting from aperture 118 b isdepicted by arrow(s) 118 a. The light 118 a is then impinging on theexample application of two blocks 119 and 120 with light cure adhesive.The light is of sufficient intensity to “cure” the adhesive 121 and thetwo blocks 119 and 120 will be affixed together by the cohesive strengthof the adhesive 121. The adhesive curing device in FIG. 11 a may be usedto cure “surface coatings” such as UV clear coats, conformal coatings,etc. The device may also be used to cure “solid-body” objects such asthose found in stereolithography processes or casted or molded objects.Examples of these “solid-body” objects are the bases and/or ear moldsfor hearing aids as well as countless applications involvingphotochemical curing of molded object in transparent or open molds.

The LED 10 bonded onto or near the tip of at least one heat pipe 64simultaneously maximizes the rate of heat transfer away from the LEDchip 10 and minimizes the frontal cross-sectional area of the heat sink68 or submount or heat exchanger. The light emitting 82 from the LEDjunction(s) 10 preferably travels in a direction that may besubstantially opposite to that of the waste heat that is transportedaxially down the length of the vapor cavity 84 of the heat pipe(s) 64and away from the junction(s). The light from the device may emit into ashaped volume that is substantially opposite to a shaped volume ofmaterial which the heat is dissipated in or transported to. The planethat separates these two volumes may be the p-n junction plane (thetransition boundary between p-type and n-type materials in asemiconductor) and/or it may be the plane that the epitaxial p-njunction is bonded to. Because the heat preferably is not distributedover a large radial distance, but rather a large axial distance, closespacing of LED or LED assemblies (or an array of assemblies) as well astheir associated optical systems (lenses, reflectors, etc.) and heatexchangers may be spaced closely together. This results in high powerLED devices and/or assemblies that are more compact, lightweight, andinexpensive to manufacture than conventional devices.

It has not been shown in the previous art to place a heat source such asa diode (or other high energy density semiconductor device) on the tipof a heat pipe because it has been considered sub-optimal. The reasonfor this is that it has been thought to be best practice to place theheat pipe into a larger heat sink with the heat source bonded to thisheat sink so as to allow the heat sink to spread the heat around andalong a larger surface area of the heat pipe. The problem with this isthat there is generally more material between the heat source and theheat pipe and the heat must travel through this excess material to reachthe heat pipe itself, as well as travel around the circumference of theheat pipe. Also, the heat will spread both toward and away from the cold(heat exchanger) end because the source is not at the tip of the hotend. All this imparts a great deal of thermal resistance between theheat source and the heat exchanger. Also, if a small high power densitydevice (like a diode) is placed near the wall of the heat pipe it can“dry-out” i.e., deplete the wick structure of fluid of a localized area.By placing the die, such as a light-emitting diode 10, on the tip of theheat pipe 64, as shown in FIG. 11, there often is not a functioning wickstructure immediately below the die, and so dry-out may be less of anissue. Most importantly, a full 360° heat spreading around the heat pipe64 is easily accomplished in a radially and circumferentially uniformmanner, thereby decreasing the likelihood of dry-out as thermal energymoves along the wick structure. The LED 10 (heat source) is at the hot(evaporating) end of the heat pipe 64 at the furthest possible pointfrom the cool (heat exchanger) end of the heat pipe. The cool end isalso known as the “condensing” end. Additionally, if the heat pipe 64 isat an angle so that the heat source at the tip is closer to the groundthan the cool (heat exchanger) end, then the heat source has the benefitof being fed coolant (i.e., water) that is aided by the force of gravityas discussed above. This coolant may pool or form a reservoir that is aready source for the wick structure due to evaporation that consumesliquid from the wick structure. This process decreases the likelihood ofthe dry-out phenomenon. Lastly, by bonding the heat source directly tothe heat pipe 64 without a heat spreader or heat sink there is one lessthermally resistive bond line for the thermal energy to travel throughbefore reaching the heat pipe 64.

FIG. 11 a is similar to the structure shown in FIG. 11, furtherincluding electrically conductive washer 122 that wedges the wire 113against the inner diameter of the sleeve 112. Incidentally, the sleeve112 may be plastic with a metal conductive strip adjacent to washer 122or it may be a conductive metal with an electrophoretic coating toprotect it from the environment. The electrophoretic coating would havea bare spot where the washer 122 contacts the sleeve 112. Similar toFIG. 11, light emitting from the exit aperture is depicted by arrow(s)118. In the example application the light 118 is shown impinging onsurface mount device 123 and its lead with solder bump 124 as shown inFIG. 11 a. The light may have an IR wavelength (could also have UV,visible, or other). In this application, the solder bump 124 will reflowfrom the heat of the light 118. The solder bump 124 may instead be alight cure adhesive bump or a heat cure adhesive bump, and may or maynot have a solder or flux component in it. The LED light (as in allembodiments) may instead be emitting from a laser diode. If the light isemitting from a laser diode, it may preferably be focused to a verysmall spot. A visible component of light (perhaps from an LED) would bepreferred if the actinic light was invisible (i.e. UV or IR). Thisnearly point source of light may be used for other applications, as wellas for heating, surface modification (i.e., ablation, etc.) orphoto-chemical reaction, etc.

FIG. 11 b depicts another embodiment of the invention for mounting theLED(s) 10 in the center of the heat pipe 64. The Kapton or othernon-conductive material ring 125 is coated preferably with copper on thetop surface 126 of the ring 125. The ring 125 has a shape, preferably asquare shape cut out in the center which allows for proper diepositioning when an external sleeve just bigger than the heat pipe 64diameter is positioned around it. A solder reflowing operation may beundertaken and when the solder 110 (that may be already coated on thebottom of the die 10) is reflowed, the ring 125 will keep it centered onthe heat pipe 64. The wire 113 that is bonded to the center of the die10 is also bonded to the top 126 of the ring 125. The conductive copper(or other conductive material) on the ring 125 has perforations 125 athat allow it to bend into a myriad of “fingers” when a conductivesleeve 112 in FIG. 11 c is brought into contact with it, thereby forminga current conduction path from the heat pipe 64 up through solder 110and die 10, through the wire 113 into the copper surface of the LED 10and then into the sleeve 112 of FIG. 11. An adhesive such as glue 115may exist below or on ring 125.

FIG. 11 c is similar to Drawing 11 b, except that the conductive sleeve112 is shown making contact with the conductive ring 125. The sleeve 112may be anodized aluminum except a small area may be masked during theanodizing operation to allow an exposed electrically conductive areathat can contact ring 125. Instead of anodizing, an electrophoreticcoating may also be employed.

FIG. 11 d further depicts the heat pipe 64 with the solder 110 and theLED die 10 on top and in the center of the heat pipe 64. The wire 113 isbonded to the center of the die 10 and also is bonded to the top of thecopper strip or Kapton ring 125 that has an adhesive section 115 betweenit and the heat pipe 64. The current connection between the die(s) 40and the sleeve 112 is made when the copper strip/Kapton ring 125contacts the sleeve 112 which is connected in a current conduction pathto the battery(s) or power supply (not shown). The die 10 may becentered by a manual or computer driven die bonder or a pick and placemachine, with or without machine vision. This is true with all die(s)depicted in this invention.

FIG. 11 e shows the sleeve 112 as a separate heat sink 68. The LED 10 isshown with attached wire 113 mounted on the tip of the heat pipe 64. Thesleeve 112, the heat sink 68 and the heat pipe 64 may preferably beelectrically isolated from each other and may be any polarity, orneutral, or a combination of polarities. They may also carry electricaltraces that can be individually addressable and traced to individualdies.

FIG. 11 f further shows the heat pipe body 64 with sintered wickstructure 127. In this application, the wick structure 127 is shown witha full coverage of operation wick structure, not only along the innerdiameter circumference walls, but also completely covering the tip bodysurface under the die 10 at the hot end of the heat pipe 64 shown inthis drawing. The solder 110 or conductive epoxy is shown as well aswire 113 which is bonded to die 10. If a thermosetting adhesiveexhibiting a high thermal conductivity such as one disclosed in U.S.Pat. No. 6,265,471 is used, it is preferred to first deposit silver (Ag)to both the die 10 and surface of the substrate (or any two contactingsurfaces) it is bonded to as this greatly decreases the contact thermalresistance (interfacial resistance) because the patented formulation ofthe adhesive allows fantastic heat transfer between silver-silverconnection and worse performance with contact between other material.

FIG. 12 shows an exploded view of the LED/heat pipe assembly as it isassembled into one or more heat sink 68 with battery pack 61 a/61 b. Theheat sink is actually two electrically isolated heat sinks 68 a and 68 bthat when “shorted” by switch 63 complete an electrical circuit from thepositive battery lead that contacts the tip opposite the LED 10 of thecopper heat pipe 64, through the LED 10, solder and wire path 201,through the sleeve 112 into the cone section of the heat sink 68,through the closed switch 63 into the bottom section of the heat sink68, through the battery pack 61 a/61 b and into the cathode end of abattery (or batteries) 202. The two heat sinks 68 may preferably beanodized aluminum or some other conductive material that may beelectrophoretically coated with a non-conducting polymer. The two heatsinks 68 may be bonded together with non-conducting adhesive (not shown)and the heat pipe 64 through hole 203 may be filled with an electricallyinsulating, but thermally conductive compound. The heat pipe/sleeveassembly may be held in place in the heat pipes by a simple set screw204. The hole 203 is simply a long hole through each heat sink 68 a and68 b that accommodates the heat pipe 64 and it may or may not have adielectric layer. The fins 218 shown in FIG. 12 b on the heat sink(s) 68may be either radial and/or at an angle in relation to the heat pipesand /or they may be axially disposed.

The light from the LED 10 emits through a transparent dielectricconcentrator 205. The light emission direction is shown by arrows 206.The most preferable embodiment contains one high power LED 10 on the endof the heat pipe. However, multiple LEDs 10 can be used at one or morecentered wavelengths. Also the LED(s) may preferably be mounted on asmall heat sink or heat spreader that is in turn mounted near or on theend of the heat pipe. Multiple heat pipes may also be employed.Individual or arrays of lenses may also be employed. If the lense is areflector it may be faceted or it may have smooth walls. It may betotally internally reflecting or it may be a metallic or dielectriccoated wall or polished wall reflector.

FIG. 12 a shows the light emitting diode 10 through reflector/lens 10a/10 b. The sleeve 112 (not shown) is electrically connected to heatsink 68 a. Switch 63 completes the electrical circuit betweenelectrically conductive heat sink 68 a and heat sink 68 b. Battery pack61 a/61 b is also electrically active (current carrying) and itsfunction, beyond containing the batteries is to connect the cathode endof the battery 202 in the heat sink 68 b. Also, O-ring 207 is shown andis attached at the connection of the heat sink 68 b and battery 202 toseal out water and to provide a smooth (tactile) feel during the threadrotation action. The light emitting device 10 shown in to FIG. 12 a maypreferably be powered by an electric cord. The device may be convectivecooled through the many fins 208 as will be shown in FIG. 12 b. Thedevice may have a gravity or tilt-type shut-off switch as will be shownin FIG. 12 c within the handpiece shown to prevent the device from beingoperated in a substantially non-gravity aided wick orientation.Furthermore, the device may further desirably have the heat pipe 68 andsleeve 112 together bent at an angle.

FIG. 12 b depicts a solid-state lighting application wherein at leastone LED die 10 is bonded to at least one heat pipe 64 which is thenfurther bonded to at least one or more heat sinks 68. In the preferredembodiment, the heat pipe 64 is oriented substantially down or verticalwith the LEDs 10 being at the lowest point near to the ground. In thisway the heat pipe 64 is said to be aided by gravity. The LED/heat pipeassembly is the same assembly depicted in FIG. 11 a, except that theheat pipe 64 is shown bonded in the somewhat spherically shaped heatsink 68 that has fins 208 that may be machined, or most preferablymolded in place. If it is molded it may be thixoformed, die cast,permanent molded, or other similar process. These processes facilitatethe high volume and low cost that is needed for a solid-state lightingproduct. All heat sinks 68 or heat exchangers 76 in this application maybe molded and may be made from an alloy of magnesium. It is understoodthat multiple LED dies 10 at multiple centered wavelengths and with heatpipes 64 (that may be bonded in one or more heat sinks) may be used. TheLEDs 10 may be electrically individually addressed and individuallymodulated or they may be in electrical series, parallel, or otherelectrical connection. Threads 209 on top portion of the heat pipe 64may be an electrically “active” component and they may facilitate ananode or cathode or ground connection. If the heat sink 68 isdielectrically coated and the threads are uncoated, they may be ofmonolithic or at least of electrically continuous design. Electricalcontact 210 above the threads 209 which is preferably the cold end tipof the heat pipe 64 is either the anode cathode or ground, but is ofpreferably the reverse polarity of the threads 209 and electricallyisolated from it. An electrical circuit could preferably be placedbetween electrical contact 210 and the power source such as within thethreaded area 209 that may step up or step down current or voltage. Thiscircuit may be present in any embodiment in this patent application. Thedevice depicted in this drawing could be threaded into a heat sink 68that may be electrically active and could absorb heat, as well as supplyelectricity.

FIG. 12 c depicts the front section (light-emitting end) of the lightsource embodiment of the present invention. This light source may beportable and fit easily in the human hand. Again, like most embodimentsin this patent application, a heat pipe 64 (or heat pipes) is (are) usedto distribute heat rapidly away from an LED 10 (or LEDs) to much largerfins on a heat sink 68. A reflector 10 b is shown and this reflector maybe made adjustable in that the cone angle of light 211 may be adjustedby the operator or during manufacture of the light source. Wire bond 212is shown running from the die(s) 10 to the heat sink 68. The heat sink68 may be anodized aluminum thereby shielding the operator formpotentially adverse electrical shock because anodize (aluminum) is avery good electric insulator. The wire bond 212 obviously contacts aspot on the heat sink 68 that is not anodized (masked duringmanufacture). The light source 211 may preferably have a rotatingbattery pack that opens or closes the electrical circuit when rotatedapproximately one-quarter turn.

FIG. 12 d shows the entire light source whereas FIG. 12 c showed onlythe front section referred as the “nose” section. The LED light is shownemitting light out of the nose by arrows 211. Heat sink(s) 68 arepreferably connected electrically by switch 63. The battery pack 61 a/61b preferably is affixed to heat sink 68 by mechanical threads (notshown) in an electrically continuous manner.

FIG. 12 e depicts a heat pipe 64 and surrounding sleeve 112 bent at anangle, which could be useful to many of the embodiments describedherein.

FIG. 13 shows the embodiment of the invention wherein multiple LEDs 10are bonded to at least one heat pipe 64 and rested on a circuit board216. The LEDs 10 are individually addressable and at least one wire 213is bonded to each LED 10 and the other end of each wire 213 is thenbonded to electrical bond pad(s) 214. These bond pads 214 areelectrically isolated from each other. In this drawing the LED(s) 10 areshown with an electrically active heat pipe(s) 64 although electricallyneutral heat pipe(s) may be used in this embodiment as well as any otherembodiment in this patent application. The heat pipe 64 may be a commonanode 11 and each LED 10 would then be controlled by varying theresistance of a resistor located between the die/wire bond and the powersupply cathode. If the heat pipe 64 is a common cathode 12, then thecurrent leading to each die 10 may be modulated directly (i.e., pulsewidth modulation and/or direct current modulation). This figure depictsa total of nine LED die. Any number of die from one to over one hundredby be employed. Also, any number of centered wavelengths from one tomore than one hundred may be employed. Most preferably, wavelengths fromthe UV to the IR are used, with 400 nm to 700 nm being the mostpreferable. This wavelength range may be used in other embodiments inthis application. The TIR reflector 10 b is also shown. It is held inplace by lens holder 215. The circuit board and/or circuit board holder216 is shown on which the lens holder 215 is placed. The hemisphericalconcave surface 114 in the reflector 10 b is shown. It is preferably ofa higher refractive index than the material used in TIR reflector 10 bso as to allow more light to escape the chip, due to TIR in the chip.Also, light rays may advantageously be bent at hemispherical concavesurface due to refraction caused by the differing refractive indices.Aspherical, parabolic, elliptical, hyperbolic or defractive surfaces maybe substituted for the hemispherical surface. The outside diameter ofthe heat pipe 64 is shown in the drawing by the solid line drawn in acircle on the left. The nine LEDs 10 depicted in the figure may be anassortment of red, blue, and green emitting LEDs. It is understood thatinstead of three LEDs of each color, only three LEDs total may be used(i.e., one green, one blue, and one red). In the figure, rectangular (orother shape) strips of each of the three primary colors could take upthe space of three of the nine squares shown in the LED 10. In otherwords, each of the three primary colors may take up one-third of theavailable (depicted) die space. This in some way might imply equalimpedance for a given die area for each color, although this might notbe true in all cases. Any organic and/or polymer LEDs could be employedin any embodiment of the invention. Red inorganic LEDs may preferably beused that are smaller in area than the blue or green LEDs. Also, due tothe human eye's ability to detect different colors at differing apparentintensities (i.e., sensitivity) more red than green, and more blue thangreen LED area may preferably be employed.

FIG. 14 depicts the device of FIG. 13 in an array formed of more thanone device of FIG. 13. Actually, in FIG. 14 an array of only threedevices are shown for clarity. Between each heat pipe 64 is shown thecircuit board 216. This circuit board may be of the conventional epoxylaminate and/or it may be of solid conductive material such as aluminumor copper with or without a non-conductive polymer or ceramic layer(laminate). It may also be wholly or partially ceramic, such as BeO,alumina, AlN, or other. Circuit traces such as thin copper or gold orplated gold may connect wire bonds 213 leading from the LED die (ordice). The lenses 10 a may touch each other and be circular at thecontacting final emitting surfaces or they may be molded into a squareshape at the final emitting surface and therefore have no “spacing”between them. Also, a final lens element (or elements) may preferably beemployed after the final emitting surface for the purpose of furtherbeam shaping or environmental protection. Additionally, circular holdersmay be employed around the lenses 10 a.

FIG. 14 a is similar to the cross-sectional view of arrayed devices ofthe FIG. 14 with the addition of holders 98 as shown around theindividual lenses or reflectors 10 a/b. Such holders could be of anyshape and size sufficient to support the individual lenses 10 a orreflectors 10 b.

FIGS. 14 b, 14 c and 14 d depict different “pixel” spacing and geometricpatterns. A “pixel” in this case is a heat pipe 64 with the nine (orother number) shown LED(s) 10 on it. Each heat pipe itself may beindividually addressable as well as each individual LED die on each heatpipe or some other combination. The ring 125 shown around each heat pipemay “nest” in a circuit board as shown in the FIG. 14 e. The heat pipes64 are shown for clarity. The wires 213 are bonded to electricallyisolated bond pads 214. When the ring 125 is nested in a circuit board,a means for connecting circuit board traces to the respective bond pads214 on the ring 125 must be employed. This means may be accomplished bycontacts connected by traces and plated through vias. The LEDs 10 maythen be controlled by the voltage and currents that are applied to themfrom the traces on the board (connected to a power source(s)), throughthe wires 213 and then to the LEDs themselves. The wires 213 may beattached (as in all embodiments) to the die(s) 10 by a wedge, ball, orother bond. Wedge bonding is preferable because the wires stay moreparallel to the board surface. Ball bonds can be advantageous in thatthe wire sticks out vertically from the chip and tends to attract thedie encapsulating polymer in a manner that pre-wets the chip and greatlyreduces the formation of bubbles as the lens or reflector is slowlylowered over the die(s).

FIG. 14 e shows the blind female recesses in the circuit board thataccommodate the rings 125 from the devices shown in FIGS. 14 b, 14 c and14 d. Contacts, vias, and traces are shown. The preferably blind femalerecess(es) 217 in the board 216 are shown. There are also preferablyblind female recess(es) 217′ depicted by dashed lines in theboard(s)that accommodate the heat pipe(s) 64. There is a thin section ofpreferably board material that is of high thermal conductivity betweenthe two blind holes or recesses 217 and 217′. In the preferredembodiment, 217 and 217′ are substantially co-axial; however this neednot be the case. There may preferably exist a board laminate 218preferably bonded on board 216. In this embodiment of the invention asshown in FIG. 14 e, the recesses 217 are actually through hole(s). Bondpads 214 that are aligned in FIG. 14 b are shown with circuit traces onboard 216. It is important to mention that through wires 213 under bondpad(s) 214 in FIG. 14 b are not shown in the figure but must be presentin order to make contact with bond pad(s) 214. The rings 125 from FIG.14 b may be square (or some other geometrical shape) and would beaccommodated by a like shaped recess 217′.

FIG. 14 f shows a device somewhat similar to the one in FIG. 14 b. Itshows the heat pipe(s) 64 co-axial to a hole through board 216. Board216 could be a “ring” similar to the ring 125 in FIG. 14 b. The board216 is shown with a thin wall surrounding the multiple dies 10. In thisdrawing, the dies 10 are shown in a “p”-side up embodiment. The activeepitaxial layer is depicted on the top edge of the die 10. May differentLED or laser diode structures and designs may be employed in allembodiments. In particular, LEDs with an optically resonant structuremay be used, as well as LEDs or LDs that utilize “quantum dots”. Hole219 is shown in the board 216 and wires 213 are shown leading from theindividual die 10 to their respective bond pads 214 and then torespective circuit traces 220. The heat pipe 64 may or may not beelectrically active. If it is active, it may be the common cathode andhave an electrical connection to the wire 213 in the board 216. Wire 213may be conductive adhesive connecting the heat pipe 64 to the circuittrace 220. Reflector 10 b is shown. Light emission is shown by thearrows pointed upward. The board 216 may be affixed to a larger boardwith hardware or some passive locking arrangement to that individualLED/heat pipe assemblies may be changed as they wear out or technologywarrants. Assemblies with multiple LEDs at multiple centered wavelengthsin or near the visible spectrum as depicted in this figure andembodiment as well as others in this patent application are ideal forautomated stage light assemblies, due to their compact, light weight,and high optical power, which may preferably be computer controlled tochange color, intensity, hue, etc.

FIG. 14 g shows heat pipe 64 inserted in a through the hole 219 of board216. Reflector 10 b is shown with LED dice 10. A two part laminatedboard with traces between the layers is depicted as top layer 216 a andbottom layer 216 b. Wires 213 in board 216 are shown as wires makingelectrical continuity between the traces 220 sandwiched between layers216 a and 216 b and the traces 220 on top of 216. It should be notedthat layers 216 a and 216 b, comprising the circuit board 216, areoptional in that the light can function without a circuit board 216 andanother means of connecting wires from a power supply to the bond pads214 can be employed in various applications. Again, fins may preferablybe attached to the heat pipe 64 to employ convection or forced aircooling.

FIG. 15 a shows four “pixels” (LED(s) on heat pipe devices) that arearrayed on a circuit board. Only four devices (each considered a“pixel”) are shown in this drawing for purposes of clarity. Actually, anarray of pixels such as 48 by 64, or 48 by 32, or 24 by 16 for examplemay be employed. Examples of pixel spacing preferably might be center tocenter spacing of 12 mm, 18 mm, 23 mm, 35 mm or 50 mm. Provisions foradjustment for uniformity, dimming, brightness, hue, color spaceconversion and gamma correction may be employed. A portion of thecircuit board 216 is shown. On the tip of the heat pipe 64 nineindividually addressable LEDs 10 are shown. Each of these LEDs 10 have awire that connects to a bond pad 214 on the circuit board 216. Pleasenote that in this embodiment there is not a separate ring 125 as shownin FIGS. 14 b, 14 c, and 14 d. The wires 213 in this embodiment leadfrom the separate LEDs on the heat pipe(s) to separate, permanentlyaffixed bond pads 214 on the circuit board 216. Only one wire 213 in theentire drawing is shown, for clarity, as well as only one abbreviatedcircuit trace 220. It should be obvious to those skilled in the art toconnect individual wires from individual LEDs to individual bond pads,and then these bond pads to appropriate circuit traces to light up theLEDs. Note how the multiple heat pipes 64 form a “pin-fin” type heatsink. All of the circumferential surface area of the heat pipes is usedto conduct heat to the ambient air that flows either by natural orforced air convection between the pins (a.k.a. heat pipes) and the heatpipes may have fins attached in any orientation to further increasesurface area. The space between the heat pipes allows air (or othermedium) to circulate and cool the heat pipes. The fins could actually beall monolithic in a honeycomb-type design wherein the bare heat pipesslide into holes in the all monolithic honeycomb heat sink. This heatsink maybe made of any thermally conductive material, and it may or maynot be forced air cooled. If the fins are not monolithic, but are joinedto heat pipes, they may be at a 45° angle (or so) to the heat pipeorientation, as well as at a 45° angle (or so) to the horizon tofacilitate naturally convective flow of air because heat will rise upthrough the fins and draw cool air in behind. Also, the air will beforced to impact the fins more directly than if they fins were mountedperpendicular (vertical) to the horizon. As in all embodiments in thisapplication the heat pipes may have some other working fluid than wateror may have some other substance added to the water. In an alternateembodiment, for example, alcohol (glycol, methanol, etc.) may be addedto protect from freezing. Also, other materials, such as aluminum, couldbe used instead of, or in conjunction with copper for the body (wall) orheat pipes. Lenses 10 a are also shown. These may be of the TIR varietyor refractive, diffractive, reflective, or a combination. When the LEDs10 on one of the heat pipe 64 are turned on in some combination, thepixel can be thought of as “on” or “active”. In general, each heatpipe's LEDs would be some combination of individually addressable red,blue, and/or green LEDs. As in all embodiments in the application“white” LEDs may be employed.

FIG. 15 b an array of heat pipes 64 that are inserted and bonded inblind holes in a board 216. The blind holes 221 are more clearly shownin FIG. 15 c. The board 216 may be a printed circuit board or simply aplate of metal (or other conductive or non-conductive material) withcircuit traces 220 leading to the LEDs 10. A “group” of three LEDs areshown in this drawing for clarity. One or more LEDs, at one or morecentered wavelengths may be used. This drawing also shows only three LED“groups” (the fourth is hidden), four lenses 10 a and three of four heatpipes 64. It is understood that those few parts are only shown forclarity and that they represent an array of perhaps hundreds that may beon a single board 216 or multiple boards that are in themselves arrayededge to edge. The heat pipes 64 that are in the blind holes maypreferably be bonded into place with a high thermal conductivityadhesive. The blind holes are deep enough that only a thin layer ofboard material exists between the bottom of the hole (where the tip ofthe heat pipe will rest) and the top of the board 216 where the LEDs 10will be bonded immediately above the bottom of the hole. In this waythere will be minimal thermal resistance from the LED flip-chipjunction, through the thin board material, through the adhesive, andinto the heat pipe 64. The circuit trace 220 may be designed such thatindividual traces lead to LED chip anode bond pads that “p” side downflip-chip LEDs 10 are soldered to, and other traces lead to cathode wirebond pads that the wires from the cathode side of the chips are bondedto. The circuit board 216 is preferably of aluminum for light weight andthermal conductivity. It is preferably anodized to provide electricalisolation form the chip bond pads, wire bond pads, and the traces to andfrom them. Other thin-film processes may be used to deposit theelectrical isolation layer. The board 216 may be made from an aluminum(or magnesium) epoxy or copper epoxy laminate. The LEDs 10 may also (butnot necessarily) be individually addressed to preferably haveintensities at different time cycles more control be made available tothe end user.

FIG. 15 c is a side view of just two (of many) heat pipes 64 of FIG. 15b clearly showing the blind holes 221 in the circuit board 216. Only twolenses 10 a are shown, for clarity and orientation, as well as a fewwire bonds 212 and a few LEDs 10.

FIG. 15 d shows a typical forced-air cooled hand-held embodiment of thepresent invention. It is understood that it may also be fixed or mounted(not hand-held) and it might be convectively cooled, i.e. no forced-air.A fan 66 is shown, with heat pipes 64 and lenses/reflectors 10 a/10 band emitting LED or VCSEL light shown with arrows pointing downward. Allthe parts as well as the LEDs 10 or VCSELs adjacent to the tips of theheat pipes 64 are enclosed in a housing 222. Electrical power may besupplied through an external cord from a power supply or from batteriesor from a combination of each or rechargeable batteries. A gravityswitch may preferably be employed wherein the switch would only beelectrically continuous when the LEDs 10 are pointed substantiallytowards the ground. This would allow a gravity aided feed in the heatpipe 64.

FIG. 15 e depicts an embodiment of the present invention wherein threeseparate LEDs 10 are disposed upon the end of a heat pipe 64.

It is understood that the arrays discussed in this patent applicationfor display or other applications may or may not have a heat pipe 64immediately below the LEDs 10. The heat pipes 64 could, for example, beonly used to transport heat and may be randomly placed below the LEDs10. The heat pipes 64 protrude from a circuit board 216 in a directionthat may be substantially opposite to the direction of the emittinglight. In this manner, they act as heat transport pins to other broadersurface area heat sinks 68 or the outside diameter of the heat pipes 64themselves which may be used as the heat emission (or heat exchanging)surface area without any additional bonded fins. Again, natural orforced convection may be employed in any embodiment. Also a phase changematerial (such as paraffin) may be used in any embodiment and maysurround the heat pipe(s). The paraffin may have a thermal conductionenhancement material in it such as copper wool or conductive particles.The circuit board 216 that the LEDs 10 are affixed to may be affixed toanother conductive (or non-conductive) plate that, in turn, has heatpipes embedded in it.

FIG. 16 shows the Vertical Cavity Surface Emitting Laser (VCSEL)embodiment of the instant invention. The drawing shows one VCSEL 224bonded to the top (tip) of a heat pipe 64. It is understood that arraysof VCSELs 224 instead of just one may be bonded to the ends of one ormore heat pipes. It is further understood that the VCSELs 224 (or forthat matter, edge emitting laser diodes) may be substituted for the LEDs10 depicted in any drawing or stated in any embodiment in this patentapplication. The heat pipe 64 is shown within a sleeve 112. The heatpipe 64 and the sleeve 112 may be electrically isolated. Also the sleeve112 and/or the heat pipe 64 may have a bend in them (0° to 90° or more).This may also be the case in any other heat pipe/sleeve combinationshown in any embodiment in this patent application. Anode 11 wire andcathode 12 are shown running from a sub-mount 14 to a low impedance“strip-line” type current/voltage carrying device. This “strip-line” hastwo thin copper foil type tape anodes 11′ and cathodes 12′ running downthe length of the heat pipe from the VCSEL to the power supply orpulser. The copper foil tapes 11′ and 12′ are insulated from each otheras well as the heat pipe 64 and sleeve 112 (or other environment)preferably by Kapton type tape 225. The VCSEL 224 may be of the highpower type (over 1 W) CW or much greater peak powers (over 1 KW). It maybe pulsed with short (such as ps pulses) or long (such as ms pulses).The wavelength range may be from the UV to the IR. The laser lightemission with arrows pointed upward is shown emitting from a partiallyreflecting output coupler mirror 226. The active region and rear mirrorare shown mounted to the conductive slug/submount 14. A transparentspacer assembly 227 is shown. Lenses 10 a may be desirably employed.

FIGS. 17 and 17 a depict a separate heat sink 68 bonded to the end ofheat pipe 64. It is understood that this heat sink 68 could beelectrolytically electro-formed onto the end of the heat pipe 64. Theelectro-formed heat sink 68 could be made of copper. In the preferredembodiment the heat sink 68 is bonded to the end of the heat pipe 64with high thermal conductivity glue. The LED 10 (or LEDs) is shown. Thelight emission from the LED 10 is shown as arrows pointed upward. Thisembodiment may also be useful for edge-emitting laser diodes. The dashedlines depict the blind hole 221 that is in the heat sink 68 toaccommodate the heat pipe 64.

FIGS. 18 a and 18 b shows an embodiment wherein the LED 10 is mounted toa flat side 64 c or spot of the formerly cylindrical heat pipe 64. It isnot necessary that the heat pipe be formerly cylindrical; it may bemanufactured “flat”. The light emission with arrows pointed upward isshown. Arrays (more than one) of LEDs 10 may be bonded to the flattenedportion of the heat sink 68 in any orientation. The LEDs 10 may besoldered directly to the copper heat pipe 64 with lead/tin or othersolder 110. This embodiment is preferable when a direct 90° sideemission in relation to the heat pipe length axial direction isrequired. This is especially useful for curing applications that requireclose contact.

FIGS. 18 c and 18 d depict a laser diode 228 mounted directly to aflattened portion 64 c of a round heat pipe 64. The negative anode wire12 is shown along with symbol (−). The cathode in this drawing is theheat pipe 64. It is marked with symbol (+). Light emission with arrowspointed is shown. Also, solder 110 is shown. An edge emitting, broadarea laser diode bar may be employed. Optional lenses may alsopreferably be employed. Lenses, such as diffractive optical elements(DOE) may also be desirably used in any embodiment to destroy thecoherence of LDs. This makes them safer and easier to market from aregulatory (FDA) standpoint. FIG. 18 c is a front view of the device.FIG. 18 d is a side view of the device. Arrays of LDs, VCSELs, or LEDs,of individual chips or combinations of all three (in any combination)may be preferably used.

FIG. 18 e shows a round heat pipe 64 that has been flattened at one end,with LEDs 10 disposed upon the flattened portion of the heat pipe 64.The center line 229 bisects the flattened portion of through the centerof the heat pipe 64. It should be noted that while this figure depicts around heat pipe 64 that has been flattened only at one end, the presentinvention includes any round heat pipe 64 that has been flattened forany portion of its length so as to accommodate the reception of one ormore LEDs 10. Additionally, the heat pipe does not have to have everbeen round, as it may be manufactured flat. This is true for allembodiments in this patent application.

It is noted that all embodiments in this application could utilizemicrochip or thin disk laser technology. For example, the active regionof a microchip laser and/or gain media of a think disk laser could bemounted on the tip of a heat pipe.

Additionally, in another embodiment of the present invention there isprovided packaged LED (or laser diode) device(s) which provide superiorthermal transfer which allows operating the LEDs at a currentsubstantially higher than manufacturer specifications and in a packagesubstantially smaller than the current state-of-the-art. The packagedLED (or laser diode) device preferably includes at least one LED, asub-mount, a flex (or rigid) circuit, and an optional TIR reflector.This packaged device may be affixed to a heat pipe. The device may beused as a discrete device, or with an array of similar devices foradhesive curing and various other applications.

FIG. 19 a depicts a high thermal conductivity material, preferably a CVDDiamond, for use as a heat spreader/submount 230. The diamond in thisfigure, preferably, is 100 microns thick and has 50 micron diameterlaser drilled through holes 219. These holes 219 facilitate the transferof a thermally, as well as electrically, conductive adhesive from top tobottom and/or bottom to top of the substrate. The holes 219 may havewalls that are purposely sloped (not parallel) to allow for a biggeropening on one side than the other to facilitate easier filling ofconductive adhesive. Other heat spreader/substrates, such as AlN or evencopper, may be used. Heat spreaders may also be metalized with a patternfor one or more semiconductor die. The metalization may or may notextend through holes that may exist in the substrate. They may bemetalized on one or both sides.

FIG. 19 b depicts nine LED die 10 shoulder to shoulder on a heatspreader/submount 230. These die may be approximately 300 microns×300microns at the top (wire bond surface) and approximately 200 microns×200microns at the bottom “n” contact surface. These dimensions allow theholes 219 shown in FIG. 19 a to not substantially fall under any diesurface. In other words, the “streets” between the bottom of the dieencompass the holes 219. Conductive epoxy may be used to bond the dies10 to the heat spreader/substrate 230. Another means of affixing may beto solder, provided that the substrate is first patterned and metalized.The holes 219 allow electrical current to flow between the top andbottom surface of the heat spreader/substrate 230. The heat spreader 230is preferably non-conductive although it could be conductive if a metalsuch as copper or aluminum were employed. It is understood that only onedie 10 may be used or multiple dies 10 may be used. They may be inseries, parallel, or other combination and they may or may not beindividually addressable. One or more center wavelengths may be employedparticularly if more than one die is used, although multiple wavelengthscan exist on one die. In general, these wavelengths span the visiblerange from the UV/visible edge to out near the visible/IR edge. Ifmultiple wavelengths are used, they may advantageously be employed toselectively target photo-initiators in adhesives or coatings, and mayalso be used to penetrate material to different depths. The devices maybe capable of being remotely adjusted for beam angle, power, intensity,hue, color, etc. Usually, for most applications with multiplewavelengths, i.e. dies having different centered wavelengths, individualaddressability is preferred. The devices in this application have thisinherent individually addressable characteristic. The heat spreader 230may preferably use only one die 10. The holes 219 through it should notbe directly under the die(s) 10, but rather out from under it (them) inthe periphery. Holes 219 could be replaced by wire bond pads in analternative embodiment. Circuit traces 220 lead to the metalized bondpads(s) 214 in FIG. 19 c. It should be understood that it is NOTnecessary to have holes 219 through the heat spreader 230. Circuittrace(s) 220 could simply lead to wire bond pad(s) 214 and a wire orwires could be bonded to the pad(s) and terminate at another bond pad asshown in FIG. 20 to facilitate completion of an electrical circuit. Thisbond pad 214 could also take the place of through hole 219′ in FIG. 20,for example.

FIG. 20 shows layer 230″ which is a flexible or rigid circuit materialwith a cut-out 231 through the center which allows the LED die(s) 10 tocome through from the layer 230″. It has wire bond pads 214 and circuittraces 220 that extend out to the preferred plated through holes 219.Each bond pad 214 may accept a wire from an LED. One trace does not havea bond pad, but rather a larger plated through hole 219′. This throughhole 219′ optionally allows the same electrically conductive glue underthe heat spreader 230 to come through and contact the trace 220connected to it. This essentially allows the electrical polarity of theadhesive under the heat spreader 230 that goes up through the holes 219in the heat spreader 230 and contacts the adhesive under the die(s) 10,to be the same polarity. In the preferred embodiment, this polarity is“negative” (although it could be “positive”) and allows multiple die toshare a common ground plane. This ground plane can then have anelectrically continuous path up through the through hole 219′ to a trace220. Note that optional through hole 219′ may preferably act as theelectrically continuous path that is on top and in the same plane as thedie(s). The preferably flex circuit 230″ in this figure is preferably ofkapton or similar, substantially non-conductive material with goldplated copper traces that are patterned, etched, and (subsequently gold,or other, plating). This circuit 230″ is available on a custom designedbasis from manufacturers. The cut-out 231 in the center may be sized tojust clear the die(s) 10 or it may be larger. It may also facilitateconductive adhesive stenciling. It is bonded to the preferably flex (orrigid) circuit material 230′ as will be shown in FIG. 20 b through theuse of a B-stageable adhesive layer. Again, it is understood that theplated through hole 219′ could be negated by replacing it with a bondpad 214. A wire 213 could then be bonded to this bond pad 214 and a bondpad or pads on the heat spreader 230 that lead, for example, to a groundplane.

FIG. 20 a depicts the “bottom view” of FIG. 20. The holes 219 and 219′are preferably plated through (i.e., the walls of the holes, notincluding the center die cut-out, are electrically conductive). This isoften accomplished through the use of a palladium emersion coatingapplied during the manufacture of the flex (or rigid) circuit.

FIG. 20 b shows the thicker circuit material 230′ and shows the topside. Note the cut-out 231′ preferably by laser means through thematerial preferably kapton or rigid FR4 Flex that allows the heatspreader 230 of FIG. 19 to fit inside. The circuit material 230′ mayalso preferably be about the same thickness as the heat spreader 230,i.e. approximately 75 to 150 microns. This circuit material 231′ withthis side shown is bonded to the bottom of layer 230″ of FIG. 20.

FIG. 20 c shows the bottom side of the material 230′ of FIG. 20 b. Notethat the round through holes 219 are preferably plated through.

FIG. 20 d shows the circuit material 230″ of FIGS. 20 and 20 a bonded tothe material 230′ of FIGS. 20 b and 20 c.

FIG. 20 e shows the bottom side of the two bonded materials depicted inFIG. 20 d. Note how the cut-out 231′ is terminated by the “membrane”like top circuit material 230″. This cut-out accepts the dimensions ofthe heat sink 68. In fact, the heat sink 68 is glued into place byplacing a drop of glue in the four corners of this cut-out 231′ and thenthe heat spreader material 230 is gently placed within the confines ofthe cut-out 231′. Note that you can clearly see the optionally platedthrough holes 219 and 219′.

FIG. 21 shows the previously described circuit material 230″ with nineLED dies 10 bonded to it with an electrically and thermally conductivemeans. The nine dies are for example only. One or more dies may be used.In this example, they are marked “p” side up, although “p” side downwith individually addressable bond pads 214 may be employed. Each die 10(or packaged die) may be controlled by a computer controlled resistiveelement between the die cathode lead 12 and a power supply, useful whenthe LED 10 is mounted “p” side down on a heat sink 68 that may have anelectrically conductive common anode. If the “p” side is not on a commonanode (each LED “p” side is electrically isolated from the rest) thecurrent may be directly modulated between the power supply and the “p”contact. Pulse-width modulation may preferably be employed. If the chipsare mounted “p” side up, they could share a common cathode and desirablybe modulated individually by a computer controlled current modulatorbetween the “p” contact and the power supply. The traces to the bondpads 214 in FIG. 21 could be etched and/or buried in a silicon or othersemiconductor layer that could be on top of a high thermal conductivitymaterial such as diamond or traces 220 could be copper on top of flex orrigid circuit 230″. Wires 213 are shown from the top of the LEDs to bondpads 214. The LEDs 10 may preferably be placed in the proper positionusing automated pick and place equipment with machine visioncapabilities.

FIG. 22 shows a ring 232 that sits on top of the circuit material 230″of FIG. 20. It is a strengthening member first, but it can also be usedas a current equalizing member between all the traces 220 if it has someelectrical conductivity. It may also serve as a pin guiding member. Thisconductivity may result from it being a metal or coated with a metal.Furthermore, the conductivity between it and the traces 220 and/or theplated through holes 219 may be established through the use of anelectrically conductive adhesive or solder. The through holes 233 of thering 232 are aligned over the through holes 219 of the circuit material230″ and adhesive may be injected in them and/or they may contain pinsthat come up through the plated holes 219 that facilitate electricalinterconnections which will be explained later in detail. The ring 232could also preferably be non-conductive.

FIG. 22 a shows the ring 232 of FIG. 22 affixed to the top of circuit230. Circuit traces 220 and wire bond pads 212 are shown. It isunderstood that circuit traces 220 and pads 212 could be a monolithiccircular annular ring around the outer periphery of circuit 230″ if allof the LEDs 10 (or a single LED) were electrically driven together inparallel and were not individually addressable. The ring 232 could beconnected to an outer sleeve by conductive adhesive to facilitateelectrical connection. The adhesive could be applied to both partsthrough a hole in the sleeve.

FIG. 22 b depicts the assembly of FIG. 22 a with a TIR lens/reflector 10a/b over the LED(s) 10. It has a hemispherical cavity in the bottom ofit (not shown) that is filled with a preferably heat curable indexmatching compound. This compound (or gel) allows greater lightextraction from the LED die due to its index matching properties. It maybe placed on the hemisphere and allowed to partially cure. This partialcure increases its viscosity. The LED(s) may be lowered into the gel ina chamber that is of a pressure lower than ambient. It may also beallowed to fully or partially cure at this sub-ambient pressure. Thisprocedure can lower the risk of a bubble formation. It is important thatTIR lens/reflector 10 a/b be lowered over the LEDs at a rate of around 1micron/second or less. Again, the hemispherical cavity does not have tohave a spherical shape. Lens/reflector 10 a/b could have metalizedwalls. It also could preferably have an annular “step” at its point ofsmallest circumference to act as an index matching compound reservoir.

FIG. 22 c shows a bottom view of the assembly of FIG. 22 b, but forpurposes of explanation the heat spreader 230 with the attached LED(s)10 is shown removed from the assembly. Shown herein is the circuit layer230″ and the reflector 10 a/b is shown for purposes of orientation.

FIG. 22 d shows the assembly of FIG. 22 c with the heat spreader 230shown. Uncured conductive adhesive 234 is shown smeared on the bottom ofheat spreader 230. It is applied in such a fashion as to make sure thatadhesive goes up the through hole 219′ to the LED die 10 (not shown) andalso, if desired or applicable, over to hole 219′ and up it. Again, thisis the case if one is trying to facilitate an electrically continuouspath from the bottom of the assembly or heat spreader 230 (or heat sink68, or slug 14) to the top surface of the heat spreader 230 in the sameplane as the LEDs. It is noted that adhesive 234 can be spread on top ofheat pipe 64 prior to the assembly of FIG. 22 d affixed on the heat pipe64. It is understood that the assembly of FIG. 22 c does not need to bemounted on a heat pipe 64 (not shown). It is quite acceptable to mountthis assembly on a circuit board and use the heat spreader 230 to spreadheat and lower thermal resistance. If not mounted on a heat pipe 64, theassembly may become a SMT (surface mount technology) device. Whenmounted to a circuit board, traces on the board could lead to platedthrough hole 219′ (which could be plated solidly through) and couldserve the purpose of either an anodic or cathodic contact. In thisdescription the heat spreader 230 could have holes in it providing apolar contact. It is preferable that solder 110 be used in thisparticular embodiment as adhesive can wander and short out the device.In this, case adhesive blob 234 would not be present. The solder 110 maybe applied to the proper places on the assembly or to proper pad(s) 214on a circuit board 216 not shown.

FIG. 22 e depicts the assembly of FIG. 22 d with a strengthening ring236 and a heat pipe 64 shown. The heat pipe 64 shown is a flattened(although it can be round) and, for example only, has an oval dimensionof 2 mm×3.7 mm×200 mm in length. The strengthening ring 236 may also bethermally conductive so as to spread some heat from the LEDs 10 to theside walls of the heat pipe 64. This may lessen the chance of “dry-out”as the heat is spread over a larger surface of the heat pipe 64. Theassembly of FIG. 22 d is affixed to the plane dictated by the top (tipor end) of the heat pipe 64 and the ring 236 that surrounds it. Athermally and electrically conductive glue may be used for theaffixation. The finished assembly may be placed in a female receptaclein a circuit board (not shown) wherein conductive “bumps” or pins couldmake contact with the plated through holes 219. These “bumps” could beattached to circuit traces 220 in or on the board 216, that could thenturn on and off the current to the desired plated through holes whichwould then result in selected (or all) LEDs turning on or off (or somelevel in between) at the selected level(s), intervals, and intensities.The “bumps” may be placed on the hole(s) 219 or on a circuit board 230(not shown) or both as will be shown and described in greater detail inFIG. 24 and FIG. 25 below.

FIG. 22 f depicts the bottom view of an alternative electricalinterconnection scheme to that described in FIG. 22 e. This scheme usesconductive pins 237, similar to nano connectors, to complete theconduction path from the LED, through the wire, through the trace,through the plated through hole, into the conductive pin(s) 237, and thepin(s) 237 into a mating female sleeve or plated through hole located ina circuit board that has appropriate circuit traces to the femalesleeves and to a controller and power supply. The assembly in thisdrawing has a different style strengthening ring 236′ than thestrengthening ring 236′ of FIG. 22 e. Heat pipe 64 is shown, but as inall drawings, has only a portion of its length depicted for clarity. Thepin(s) 237 could alternatively be placed in a circuit board and femalereceptacles or plated through holes in ring 236′ and/or hole(s) 219 ofFIG. 20.

Note how the pins(s) 237 protrude from both the top and bottom of ring236. The top portion of the pins can go into the holes in ring 232 ofFIG. 22 and the bottom portion slide into appropriate female receptaclesin a circuit board as will be shown and described in detail in FIG. 23.The circuit board may have an array of complete LED assemblies whoseLEDs are individually addressable. These arrays may be used forapplications such as curing glues, inks, or coatings. The arrays usedfor curing or other photo initiated chemical reactions may have multiplewavelengths strategically turned on at proper times at strategicwavelengths and intensities. The arrays could be activated andcontrolled remotely using wi-fi or blue tooth or other wireless meansand protocols. This would greatly reduce the demands of routing tracesto all devices on a large and densely packed circuit board.

FIG. 22 g shows a complete assembly with the assembly of FIG. 22 daffixed to the assembly of Drawing 22 f. The pin(s) 237 may be gluedinto the holes of ring 232 (not shown) as well as the preferably platedthrough holes 219 (not shown). One, or possibly more, pins may be usedas a ground (cathode). If a pin or pins are used they may be glued withelectrically conductive adhesive 234 or solder 110 into hole(s) 219 thathas a trace leading to hole(s) 219′ as shown in FIG. 20. This mayfacilitate the negative (cathode) connection of the assembly. There arepreferably many different embodiments possible for facilitating a groundconnection. The ground connection may take place on the same plane asthe bottom of the LED(s), on the bottom of the heat spreader, acombination of each, or some other possibility that one skilled in theart could conceive.

FIG. 22 h depicts one aspect of the present invention, a total internalreflecting (TIR) lens 10 a that includes a concavity 99 at the end ofthe lens 10 a within which an LED 10 is to be disposed. Note that theconcavity 99 could be filled with an index-matching gel to surround andencapsulate the LEDs disposed within the cavity of the lens 10 a. TheTIR reflector 10 a depicted in this figure may be molded of, forexample, Zeonex E48R and it may be produced by amicron-tolerance-capable injection-molding machine. The index-matchinggel that surrounds and encapsulates the LEDs 10 has a refractive indexbetween the refractive index of the LED substrate and/or epitaxiallayers and that of air, and preferably has a refractive index greaterthan 1.59.

FIG. 23 a shows an array of heat pipes 64 inserted into circuit board218. Preferably, the length of the heat pipes 64 are 200 mm and thedimensions of the board 218 are 25 mm×100 mm stacked. These dimensionswould allow two 100 mm×100 mm stacked fans 66 to blow air though thearray of heat pipes 64 in a dimensionally compact and space conservingmanner. Note that by using oval (flattened) heat pipes, air flow betweenthe heat pipes is torturous which results in turbulence, which increasesheat transfer. Also note that the oval shape(s) in the circuit board(s)218 may “key” the entrance of the heat pipes such that the assembly ofFIG. 22 g could be affixed to this board by the friction of its pins 237matching up with the array of small holes 238 in this figure. The smallholes 238 contain the female receptacles (or sockets) that arethemselves connected to circuit traces that ultimately control the LEDs.It is to be noted that instead of pins and sockets, “bumps” could takethe place of either-the pins, or sockets or both.

FIG. 23 b depicts an alternate arrangement for the heat pipe 64 ovals ofFIG. 23 a. It is an even more tortuous path for more turbulence betweenthe preferably oval heat pipes. Round or other shaped heat pipes 64 maybe used. Note the sockets 239 for pins 237 and the traces to thesockets.

FIG. 24 shows the LED (or laser diode or VCSEL array) assemblies of FIG.22 g being inserted into the circuit board assembly 216 of FIG. 23 a.Note the oval shaped holes 238 that “key” and/or accept the oval heatpipes 64. The optional blind circular holes 221 in the top portion ofthe circuit board 216 accept the strengthening rings of the assembliesof FIG. 22 g. Also, note the circuit traces 220 (only a few are shownfor clarity) on circuit board 216 beneath the top board layer thatcontains the blind circular holes 221. Also the holes 238 contain thefemale receptacles for pins 237. The receptacles in 238 are connected tothe traces 220 and the traces lead to a controller and/or power supply.Each LED 10 assembly on each heat pipe 64 of FIG. 24 is thought of as a“pixel” that is individually addressable. Each “pixel” may also havenine (for example only) individually addressable LEDs. The waste energyfrom the LEDs 10 is carried straight back through the heat pipes 64 anddistributed across the circumferential surface area of the heat pipes 64which is somewhat analogous to a the operation of a “pin” in a “pin-fin”heat sink. In the most preferable embodiment, a red, a green, and a blueLED 10 are mounted on or in the region immediately adjacent to the tipof the heat pipe 64 and each are electrically individually addressable.It is understood that multiple red, green, or blue LEDs may be mountedtogether and/or in any combination and have different centeredwavelengths. The traces 220 are also shown in FIG. 23 b and the femaleholes 238 are also depicted and described in FIGS. 23 a and 23 b as wellas this FIG. 24. Optionally a second strengthening board 240 on top ofthe board 216 has circular, rather than oval holes. These circular holesaccommodate the round strengthening ring(s) 232.

FIG. 25 shows the assembly of FIG. 22 b and FIG. 22 d within an outersleeve 112. The sleeve 112 has a hole through it by which a conductiveadhesive 234 or solder 110 may be injected. This adhesive can then serveas an electrical conduction path between the conductive ring 232 of FIG.22 and the conductive sleeve 112. This sleeve may be made from aluminumand it may be anodized or electrophoretically coated which serves as anelectrically isolating coating. However, the through hole 112 is notcoated, thereby the adhesive can contact an electrically conductingsurface. The sleeve 112 and the heat pipe 64 are electrically insulatedfrom each other by way of example in this FIG. 25. For purposed ofdrawing orientation, the reflector/lens 10 a/10 b is shown with thearrows depicting light emitting from the LED or LD device. In thisfigure, the heat pipe 64 is the “anode” and the current goes through theLED and through the wire 213 and then into the conductive ring 232 andthen into the conductive adhesive 234 and finally into the conductivesleeve 112. The heat pipe 64 is connected to the “positive” battery orpower supply terminal and the sleeve 112 is connected to the “negative”battery or power supply terminal, the polarity may be reversed dependingon polarity of LED die/dice.

In an additional embodiment, there is shown LED packages according tothe present invention manufactured and assembled using Printed Circuitboard (PCB) techniques described herein. Referring to FIG. 26 a, thereis shown a first layer 260 made preferably of polyimide and have apreferred thickness of around 0.001″ to 0.002″. This layer 260 may havephoto imaged and etched metal, preferably copper, circuit traces 220.The first layer 260 may be in sheet form of approximate dimensions 12″to 18″ and many, if not all succeeding layers may have the sameapproximate dimensions. This first layer 260 is bonded to the secondlayer 261 which is also preferably polyimide and is approximately 0.004″thick. This layer 261 may have a square hole laser cut in it toaccommodate the eventual insertion of a heat spreader 230. This heatspreader 230 is preferably of a highly heat conductive material such asCVD diamond as mentioned before. LEDs or LDs 10 may be bonded to theheat spreader 230 and have wire bonds leading to traces 220. Stiffeners262 and 262′ may be bonded to layers. These stiffeners are alsopreferably of a polyimide material which is available in thicknessesaround 0.040″. These stiffeners could also be injection molded plasticand assembled individually rather than in board format. The stiffenersmay be assembled individually if the layers 260 and 261 are manufacturedwith a real-to-real or roll-to-roll flex circuit manufacturing process.The lens and/or reflector 10 a/b may be bonded on or over the LEDs orLDs 10 while all layers 260, 261, 262 and 262′ are in “panel” format,i.e., components are not yet singulated from the “panel” or “board”. Allthe layers may be registered (aligned) to one another as they arebonded. The reflectors or lenses may be assembled in trays to match thecenter to center spacing of the LEDs 10 or LD devices on the panels(boards). The tray of reflectors or lenses 10 a/b may then be loweredinto the panel of LED/LD devices. In such a fashion the reflectors orlenses 10 a/b may be assembled over or on the LED/LD devices in an arrayformat to affect high volume manufacture. Pins 237 may also be addedwhile in panel format. Solder bumping, stud bumping, etc., may also beaccomplished while in panel format. After all layers and components havebeen bonded and/or assembled, the individual LED or LD devices may belaser singulated from the panel. A UV laser system may be employed forthis task. The LED or LD devices (or “packages”) are singulated by thelaser cutting through all of the layers and thereby separating thedevices from the panel of laminated layers. Polyimide is a preferredlayer material because it is laser cut very cleanly and efficiently.Automated pick and place equipment, as well as adhesive dispenseequipment, may be employed during all phases of assembly. Thelenses/reflectors 10 a/b may be arrayed on trays, on the UV tape,electro-static or vacuum chuck whether assembled in array/panel formator assembled individually using automated pick and place equipment.

FIG. 26 b shows an array of LED packages manufactured according to thepresent invention after the packages have been assembled and thensingulated by laser-cutting.

FIG. 26 c is an exploded view of one post-singulation LED packagemanufactured according to the present invention.

FIG. 27 shows an individual device similar to devices shown in FIGS. 26a, 26 b and 26 c, except that the preferably polyimide circuit layer 260is bonded not to another polyimide layer 261 (that has a cut out in itfor heat spreader 230 as shown in FIGS. 26 a and 26 c), but is insteadbonded to a monolithic, highly thermal conductive heat spreader withoutany surrounding polyimide layer 261. Layer 263 can be pre-laser cutdiamond and assembled using pick and place equipment while the LEDdevices still exist in panel format i.e., stiffener layer 262′ andpolyimide circuit layer 260 have not been laser separated from thepanel, or layer 263 may be a large wafer, (preferably 1 foot diameter,)and this wafer may be bonded to the polyimide circuit layer 260′ whichis also bonded to stiffener layer 262′. Both layers 260 and 262′ mayalso preferably be 1 foot diameter, similar to 1 foot diamond layers263. Two one foot diamond layers 263 may preferably be bonded on topolyimide layer 260 or layer 262′, as layer 260 is optional if circuittraces 220 are deposited directly on 263.

FIG. 27 a shows a bottom-side view of the LED package of FIG. 27 whereinthe no cut-out bottom layer 263 is a highly thermally conductivematerial such as diamond. Holes through this layer 263 may be laserdrilled and plated through after a first conductive metal “seed” layeris first deposited by vapor or liquid means.

FIG. 28 a shows a side view of the LED packaged device of FIG. 27. TheTIR reflector 10 a/b′ has its elliptical or parabolic side wall portionsignificantly shortened in overall length as opposed to that ofreflector 10 a/b in FIG. 26 a. This shortening in length increases theoutput divergence of the light as opposed to a longer side wallreflector. Also, this figure depicts a package that is more “hermetic”in its environmental sealing from contaminants. This is accomplished bythe top surface of reflector 10 a/b′ having a larger flat plate-likeintegral “hat” 264. This “hat” 264 sits down in a counter bore instiffening ring 265. Note the LEDs 10 for the purpose of drawingorientation. Epoxy or solder or other adhesive is used to seal “hat” 264to stiffening ring 265. Element 266 is also a polyimide circuit layer.The heat spreader is denoted by 230.

FIG. 28 b depicts an LED package similar to that in FIG. 28 a, exceptthe polyimide or other non-conductive material 266 is of greaterthickness and the concave hemispherical portion of reflector 10 a/10 b′is of less curvature. The circuit layer 266 is nearly as thick as theLEDs 10 are. The reason for this is that the LEDs 10 shown have theepitaxial layer 267 on top of the LED 10 as opposed to a “flip-chip”structure wherein the epi layers are on the bottom of the chip, where itis bonded to a submount or heat spreader 230. Since the LED structure ison top, the circuit layer 266 may be thicker without absorbing muchemitted light out of the sides of the chip. Primarily the advantage isthat the excess index matching gel 268 that surrounds the chip(s) isless likely to flow on the sides of the TIR reflector 10 a′/b′ anddestroy the TIR properties i.e., couple out light through the sidesbecause the gel 268 has a cavity to flow into that is not in such closeproximity to the reflector wall. The cavity is defined by the thick(high) side walls of the square cavity that is laser cut-out or punchedin circuit layer 266. The heat spreader 230 may be thicker than layer261. As such it would “stick out” a little and may give clearance forsolder bumps used as connection devices near the outer diameter“periphery” of the device. This clearance helps to alleviate some stressin the solder bumps if the package is not so firmly pulled down onto thecircuit board. The layer 267 may be of essentially the same thickness aslayer 262. Lastly layer 267 may be thinner than layer 262 which wouldallow extra room for the bonding means of layer 267 to the heat pipe 64or circuit board 216. This extra room can alleviate stress in the bondlayer.

FIG. 29 shows a bottom-side view of an LED packaged device of FIG. 27wherein the hypotenuse of the heat spreader 230 is almost as long as thecord of the diameter of the captive polymer layer 269. This greatersurface area of the heat spreader 230 allows a greater area to conductheat through in a small diameter package, which by nature has a smallerdiameter polymer layer/ring 269. If nine individually addressable LEDsare employed, there is an inherent need for nine conductors plus aground. These nine conductors may be plated through holes 219 throughthe heat spreader 230. Importantly, three such conductors are locatedsymmetrically on each of the four sides of the heat spreader 230. Thehole(s) 219 are connected to circuit traces found on top of the heatspreader 230. These traces are then wire bonded to the LEDs or LDs 10.These hole(s) 219 may be connected to a circuit board that controls thepackaged device via solder bumps on the device and/or board, conductive(anisotropic or isotropic) adhesive bumps on the device and/or board,stud bumps on the device and/or board, pins—preferably compliant on thedevice and/or board, solder paste on the device and/or board, solderpads or preforms on the device and/or board, or anisotropic conductivefilm. Conductive adhesive or solder paste may be injected in holes 219.This list is by no means meant to be exhaustive or all inclusive.

FIG. 30 a depicts a flattened flexible heat pipe 64 with LED's or LD's10 bonded to it. This heat pipe could be less than 1 mm or also bethicker than 1 mm. One or more LEDs or LDs 10 may first be mounted ontoa submount, individually or collectively i.e., monolithic submount. Theheat pipe 64 may conduct electricity and, as such, be either an anode ora cathode. Arrows from LEDs 10 depict light emission. The LEDs 10 may bein series, or in parallel or be individually addressable. This flexibledevice may be encapsulated in a transparent polymer. It may be used as astrap like device to wrap around a human or animal body part for lighttherapy. This same purpose may result from the use of device in FIG. 30b.

FIG. 30 b depicts the heat pipe of FIG. 30 a. This heat pipe 64 has oneor more organic Light Emitting Diode(s) (OLED) 10′ bonded to it. Thisallows for a very thin structure and the heat pipe 64 is preferablylonger than OLED 10′ and transports the waste heat away from the OLED10′ to a heat sink 68 or dissipates the heat energy to ambient air.

FIG. 30 c shows the heat pipe 64 bent around a finned heat sink 68. Thisheat sink may be made up of one or more extruded, molded, or machinedheat sink(s) 68. The finned heat sinks 68 allow for more surface areafor the heat from the LED device(s) 10 to be dissipated, through eithernatural or forced air convection. The device in the drawing may be usedfor applications requiring a large emitting area with or withoutcorresponding high or greater than 10 W output power. High output powermay be used in various such applications utilizing LED 10. treatment. AnOLED 10′ may be used where LED 10 is shown.

Referring to FIG. 31 a, there is shown an array of LEDs 10 on a diamondsubmount 301 which is then bonded to a heat pipe 64. The diamondsubmount 301 is non-conductive, although it could be doped with boron tomake it electrically conductive. The top surface 301 a of the diamond301 is metalized. This metalized layer serves as the “p” contact 303metalization and is the common “p” contact for all of the LEDs (1-N innumber) 10. “n” wire 302 and “p” wire 303 are shown only one forclarity. The LEDs 10 in this embodiment are preferably “metal-backed”LEDs, but various other LEDs may be used. This depiction is ideal foruse in various applications preferably without a lense. A transparentflat (planar) window is preferred.

FIG. 31 b depicts an array of four (although 1-N may be used) LEDs 10.In this embodiment, the “n” 302 and “p” 303 contacts are on the sameside of the chip and the chips are connected in electrical series. Thisarray may be placed on a heat pipe 64 similar to FIG. 31 a.

All the devices in this patent application can be used with blue (0.465mm) light to activate photo initiators or other chromophors orsensitizers in curing adhesives or composites or other substances, aswell as used in devices that may or may not contain light sensitizers,chromophors, or photoinitiators. The devices of the present inventionmay be used in conjunction with a variety of different compositionswhich are curable using electromagnetic radiation, as described herein.For example, compositions which harden or crosslink to form coatings,sealants, adhesives or articles of manufacture may be subjected toradiation emitted from the inventive devices to effectuate hardening orpolymerizing. A wide variety of materials and compositions may beemployed. For example, compositions including polyolefins, acrylates,epoxies, urethanes, polyesters, acrylimides, cyanoacrylates, silicones,polyamides, polyimides, polyvinyl compounds, latex compounds, amongothers, may be cured using radiation emitted from the present inventivedevice. These compounds rely on a variety of different chemicalmechanisms to harden or polymerize. Generally, the ability to polymerizeusing light radiation, includes the use of compounds or complexes whichinitiate or induce or otherwise accelerate the polymerization process.Frequently, one or more of these additional compounds, usually referredto as photoinitiators, photosensitizers or chromophors, are added to thepolymerizable material to enhance both the speed and/or thoroughness ofthe cure.

Examples of useful radiation curable compositions particularly includeanaerobic compositions, such as those described in U.S. Pat. Nos.4,415,604; 4,424,252; 4,451,523; 4,533,446; 4,668,713 and 6,150,479, allto Loctite Corporation, the subject matter of which are entirelyincorporated herein by reference.

Additional information with respect to anaerobic compositions isprovided in Structural Adhesives, Chemistry and Technology, Chapter 5,Ed. By S. R. Hartshorn, 1986 Plenum Press, N.Y., the subject matter ofwhich is incorporated herein by reference.

Particularly useful photoinitiators include ultraviolet lightphotoinitiators, which are capable of curing mono and polyolefinicmonomers. These include benzophenone and substituted benzophenones,acetophenone and substituted acetophenones, benzoin and its alkyl estersand xanthone and substituted xanthones, among others. Specificphotoinitiators include diethoxy-acetophenone, benzoin methyl ether,benzoin ethyl ether, benzoin isopropyl ether, diethoxyxanthone,chloro-thio-xanthone, azo-bisisobutyronitrile, N-methyldiethanol-amine-benzophenone and mixtures thereof.

Other examples of initiators include visible light initiators such ascamphoroquinone peroxyester initiators and 9-fluorene carboxylic acidperoxyesters.

The preferred embodiments described herein are intended in anillustrative rather than a limiting sense. The true scope of theinvention is set forth in the claims appended hereto.

1. (canceled)
 2. A device for providing light in a predetermineddirection, the device comprising: a heat pipe having a first and secondend; a light emitting device mounted adjacent to the first end of theheat pipe and electrically connected to the heat pipe; and a sleevearound the light emitting device and the heat pipe; wherein said sleeveis electrically insulated from said heat pipe and said light emittingdevice is electrically coupled to said sleeve. 3-4. (canceled)
 5. Alight emitting apparatus comprising: a heat pipe having an evaporating acondensing end; a light emitting device mounted on the evaporating endof the heat pipe; and a color mixing totally internally reflectingconcentrator in optical communication with the light emitting device. 6.The device of claim 5, further comprising: at least two light emittingdevices emitting at substantially different wavelengths.
 7. The deviceof claim 5, further comprising: individually addressable light emittingdevices.
 8. The device of claim 5, further comprising: pulse widthmodulation of the light emitting devices.
 9. A light emitting device,the device comprising: a substrate having at least one heat pipe; atleast two light emitting devices mounted on the substrate; and awavelength mixing substrate, each light emitting device a differentwavelength; wherein each light emitting device is in opticalcommunication with said wavelength mixing substrate.
 10. The device ofclaim 9 wherein the wavelength mixing substrate is refractive micro lensarray.